“It’s at the very least an unfortunate decision that will embolden the regime and prolong the suffering,” General Martin Dempsey, chairman of the Joint Chiefs of Staff, told reporters at the Pentagon when asked about the weapons shipment.

“So it’s ill-timed and very unfortunate,” he said.

There was no direct comment on the shipment from Moscow, although Dmitry Peskov, Russian President Vladimir Putin’s press secretary, reiterated Russia’s long-held position that it will remain “true to its contractual obligations under previously signed contracts.”

One U.S. official, speaking on condition of anonymity, said the Yakhont missiles were delivered recently, although the precise timing was unclear. They fly at just over 2.5 times the speed of sound, have a range of about 300 kilometers (185 miles) and pack a huge punch from their 200 kg (440 pound) warhead, according to Nick Brown, editor of IHS Jane’s International Defense Review.

“They are hard to detect and even harder to shoot down or decoy away, so they’re a powerful tool for keeping warships a long way off the Syrian shore,” Brown said.

The disclosure comes just over a week after United States and Russia agreed to convene a conference to try to stop the war. But the initiative faces growing obstacles, including French opposition to inviting Iran.

The Russian arms transfer could intensify a push by some lawmakers in Congress for the United States to deepen its role in Syria, particularly after President Barack Obama’s government acknowledged preliminary intelligence that Assad’s forces likely used chemical weapons.

“We can watch from the sidelines as the scales are tipped in Assad’s favor, or protect U.S. national interests by supporting the armed opposition striving to build a new Syrian future,” said Senate Foreign Relations Committee Chairman Robert Menendez.

But many U.S. officials fear weapons could fall into the wrong hands. Reuters on Friday reported that al Qaeda’s Iraq-based wing is eclipsing in Syria the Islamist Nusra Front, which has been fighting to oust Assad. Al Qaeda in Iraq includes thousands of foreign fighters whose ultimate goal is not toppling Assad but anti-Western jihad.

Obama said Thursday he would consider both diplomatic and military options to pressure Assad, but insisted that U.S. action alone would not be enough to resolve the Syrian crisis.

REGIONAL WAR

The two-year-old civil war in Syria between Assad’s forces and rebel fighters has killed an estimated 80,000 people and forced more than 1.5 million to flee the fighting.

It has also drawn in neighbors. Israel attacked Iranian-supplied missiles stored near the Syrian capital earlier this month as the weapons awaited transport to Assad’s Lebanese guerrilla ally Hezbollah.

Israel has also been alarmed by the prospect of Russia supplying S-300 advanced air defense missile systems to Syria.

Asked about the S-300, Dempsey said: “It pushes the standoff distance a little more, increases risk, but not impossible to overcome.”

“What I’m really worried about is that Assad will decide that, since he’s got these systems, he’s somehow safer and/or more prone to a miscalculation,” Dempsey said, referring broadly to Syrian capabilities.

A spokesman for Russia’s state arms-exporting monopoly, Rosoboronexport, would not comment when asked about the shipment of a new batch of Yakhont missiles to Syria.

Russia previously delivered Yakhont missiles in 2011 in a deal estimated at $300 million.

U.S. Defense Secretary Chuck Hagel cautioned that the escalation of the Syrian conflict posed risks to Russian interests as well.

“What we don’t want to see happen, the Russians don’t want to see happen, is for Syria to erupt to the point where we may well find a regional war in the Middle East,” Hagel said at the news conference with Dempsey.

“So we continue to work with the Russians on their interests and everything we can do to convince the powers that are involved in the region to be careful with escalation of military options and equipment. We’ll continue to work through that.”

(Additional reporting by Patricia Zengerle in Washington, Tim Heritage and Thomas Grove in Moscow; Editing by Doina Chiacu and Philip Barbara)

One of the officials, who spoke on condition of anonymity, said the latest Yakhont surface-to-air missiles were delivered recently. The transfer of the missiles was first reported by the New York Times.

There was no immediate comment from the Russian government.

The disclosure comes just over a week after U.S. Secretary of State John Kerry suggested that he raised the issue of arms transfers to Syria during talks in Moscow this month.

The Russian arms transfer could intensify a push by some lawmakers in Congress for the United States to deepen its role in Syria, particularly after President Barack Obama’s government acknowledged preliminary intelligence that Assad’s forces likely used chemical weapons.

“We can watch from the sidelines as the scales are tipped in Assad’s favor, or protect U.S. national interests by supporting the armed opposition striving to build a new Syrian future,” said Senate Foreign Relations Committee Chairman Robert Menendez.

Menendez is the author of legislation that sanctions arms and oil sales to Assad, while providing lethal arms and training to the Syrian opposition.

But many U.S. officials fear weapons could fall into the wrong hands. Reuters on Friday reported that al Qaeda’s Iraq-based wing is eclipsing the Islamist Nusra Front. Al Qaeda in Iraq includes thousands of foreign fighters whose ultimate goal is not toppling Assad but anti-Western jihad.

Obama said Thursday he would consider both diplomatic and military options to pressure Assad, but insisted that U.S. action alone would not be enough to resolve the Syrian crisis.

The 2-year-old civil war in Syria between Assad’s forces and rebel fighters has killed an estimated 80,000 people and forced more than 1.5 million to flee the fighting.

The United States and Russia have agreed to convene a conference to try to stop the war, but no date has been set.

HARD TO DETECT

The anti-ship missiles supplied by Russia are designed to keep hostile ships away from Syrian waters. They fly at just over 2.5 times the speed of sound, have a range of about 300 kilometers (185 miles) and pack a huge punch from their 200 kg (440 pound) warhead, according to Nick Brown, editor in chief of IHS Jane’s International Defense Review.

“They are hard to detect and even harder to shoot down or decoy away, so they’re a powerful tool for keeping warships a long way off the Syrian shore,” Brown said.

A spokesman for Russia’s state arms exporting monopoly, Rosoboronexport, would not comment when asked about the shipment of a new batch of Yakhont missiles to Syria.

Russia previously delivered Yakhont missiles in 2011 in a deal estimated at $300 million at the time.

Russian Foreign Minister Sergei Lavrov has defended Russia’s arms sales to Syria by saying that Moscow is only fulfilling previously sealed contracts and did not want to lose its reputation as a reliable supplier.

Russia, which has protected Assad from three consecutive U.N. Security Council resolutions aimed at pressuring him to end violence, has been a large supplier of arms to Syria.

Moscow sold nearly $1 billion worth of arms to Damascus in 2011 though its sales fell significantly last year, according to data released by Moscow-based defense think tank CAST.

U.S. officials also confirmed a report that Russia has deployed a dozen or more warships to patrol waters near its naval base in Syria.

(Reporting by Phil Stewart and Patricia Zengerle in Washington and Thomas Grove in Moscow; Editing by Doina Chiacu)

On Tuesday, the military disclosed that another one of its advocates for victims of sexual assault was himself being accused of sex crimes, including allegations linking him to prostitution.

Hagel, in his initial response, ordered the retraining and recertification of U.S. military personnel whose job it is to work to prevent sexual assault and assist the victims. But the Pentagon made clear Wednesday that Hagel is open to further actions.

But the latest scandal may have been the last straw for Congress. Lawmakers have issued a string of statements vowing legislative action, such as setting job requirements for people who work with sexual assault victims.

Other lawmakers and advocacy groups are calling for changes to military law that would allow prosecution of sex crimes to be handled by a group of experts outside the victim’s direct chain of command.

“The military has made it clear that it cannot handle this problem alone and it is time for decisive action by Congress,” said Adam Smith, the ranking Democrat on the House of Representatives Armed Services Committee.

He and other lawmakers on the Senate and House panels that oversee the Pentagon have vowed to use this year’s annual defense policy bill to address the sexual assault problem.

Democratic Senators Claire McCaskill of Missouri and Amy Klobuchar of Minnesota introduced a bill on Wednesday to force Hagel to take action to strengthen sexual assault prevention programs, including improving the training and qualifications of those who work in those jobs.

Senator Kirsten Gillibrand, a New York Democrat, is planning to introduce legislation on Thursday that would remove responsibility for prosecution of sex crimes out of the military’s chain of command.

“Saying the military has a cultural problem in regard to sexual assault and sexual misconduct is a glaring understatement,” said Representative Niki Tsongas, a Democrat from Massachusetts. “At worst, this is a deep-rooted and widespread acceptance of unprofessional, inappropriate and criminal behavior.”

The pressure for action comes after department’s annual report on sexual assault in the military released last week found that unwanted sexual contact complaints involving military personnel jumped 37 percent, to 26,000 in 2012 from 19,000 the previous year.

The report came a day after the officer in charge of the Air Force sexual assault prevention office was charged with groping a woman while drunk in a parking lot not far from the Pentagon. And on Tuesday, the Army revealed a sergeant in the sexual assault prevention office at Fort Hood was under investigation.

The pressure for action has put the Pentagon on the defensive. Asked whether retraining and recertifying people who assist sexual assault victims was a sufficient response, Hagel’s spokesman George Little said training was “foundational” and was accompanied by other actions.

“We’re not focused solely on PowerPoint slides,” Little told reporters. “We’re focused on taking real steps that we believe, in combination, can at least help advance the ball on progress.”

He said the retraining effort was not necessarily limited to recruiting officers and those who help sexual assault victims, but could be expanded to other job classifications as well.

And while Hagel last week publicly opposed removing responsibility for sex crimes from the military chain of command, Pentagon officials since then have emphasized his willingness to be flexible and work with members of Congress.

“He is open to all options. I wouldn’t want to prejudge where he might land ultimately, but he wants to work closely with the United States Congress to see what ideas they have to try to address this problem,” Little said.

(Reporting by Phil Stewart and David Alexander; Editing by Lisa Shumaker)

The U.S. defense budget has taken the single biggest hit from automatic spending cuts, known in Washington as the “sequester,” and Hagel said he had tried to spare civilians the financial hardship ahead by first cutting elsewhere.

“We did everything we could not to get to this day, this way,” Hagel told an audience of Defense Department employees.

“But that’s it. That’s where we are … And I’m sorry about that.”

For those of the more than 600,000 civilian defense employees affected, the decision translates to a salary cut of roughly 20 percent during the furlough period – which runs from July 8 until the end of the fiscal year on September 30.

Although the total will vary, most civilian employees will be on unpaid leave for 11 days, shorter than the earlier Pentagon estimates of 14 days issued in March and 22 days in February.

But many civilians had hoped Hagel would find other ways to cut the budget or allow individual branches of the military to shield the civilian employees entirely. The move is expected to save $1.8 billion.

Although civilians will be able to challenge their furloughs, personal issues like financial hardship will not be taken into account, one U.S. defense official said.

Only vital missions are being protected. A second U.S. defense official, briefing reporters, said more than 120,000 civilian employees would be exempted from furloughs, including employees stationed in combat zones and medical personnel.

Employees in Navy shipyards are also being exempted because of fear their absence would delay maintenance of nuclear ships, according to an attachment to a memo by Hagel to Pentagon leaders released to reporters.

“No one service, no one’s going to be protected more than anybody else,” Hagel said.

MORE FURLOUGHS NEXT YEAR?

The mandatory budget cuts – which were included in a 2011 law aimed at reducing the federal government’s wide deficits – took effect on March 1 and total $109 billion through September 30, including a $46 billion reduction in defense spending.

The cuts will deepen in the coming years unless Congress acts to reverse them.

Indeed, Hagel offered faint hope to Pentagon employees that the situation will improve in the 2014 fiscal year, when the sequester will impose an additional $52 billion in cuts to projected Defense Department spending.

“I can’t guarantee you that we’re not going to be in some kind of a similar situation next year,” Hagel said, asked by one employee for any assurance more furloughs were not on their way.

There was limited reaction from Congress, with concerned lawmakers – including those representing military-heavy districts – calling for a need to free the Defense Department from the automatic cuts.

But it was unclear whether the furloughs would create any additional momentum in Congress, where gridlock has thwarted compromise on budget by Democrats and Republicans.

U.S. military leaders have warned the cuts will erode the military’s readiness to respond in the future to global tensions – sobering words as the Pentagon weighs threats from North Korea, advances in Iran’s nuclear program and the fallout from Syria’s civil war.

Hagel noted steps the Pentagon has already taken to slash costs, including the Air Force cutting flying time and the Navy and Marine Corps scaling back training and deployments. The Navy decided, for example, to reduce the presence of U.S. aircraft carriers in the Gulf from two carriers to one.

“Even after taking all these actions, we are still short of needed operating funds,” Hagel said in his memo.

The next steps for the Pentagon are unclear. Last month, Hagel said in a major policy speech that he had ordered a review that could lead to additional belt-tightening measures such as reducing the number of generals, paring back the civilian workforce and moving to stem spiraling costs of new weapons.

The Pentagon is also urging Congress to move forward with a new round of military base closures. Closing domestic military bases is deeply unpopular with lawmakers due to the damage such cutbacks can cause to local economies.

(Reporting by Phil Stewart; Editing by Will Dunham and Mohammad Zargham)

Hagel will announce the decision at a town hall meeting with
Defense Department employees scheduled for 2:30 p.m. EDT (1630
GMT), U.S. defense officials told Reuters, speaking on condition
of anonymity.

The furlough is shorter than the earlier estimates of 14
days issued in March and 22 days in February, but is still going
to be deeply unpopular with the Pentagon workforce. Officials
have cautioned it could discourage civilians from joining the
department, sending them instead to work in the private sector.

“He made this decision after carefully studying all of the
options,” said one U.S. defense official, adding that Hagel was
not happy about the move but that it was necessary to comply
with a belt-tightening law.

A second U.S. defense official, also speaking on condition
of anonymity, said more than 600,000 employees would go on
unpaid leave but could not say precisely how many. They would
not start their leave for several weeks, the official added.

Defense spending has taken the single biggest hit from
automatic spending cuts, known in Washington-speak as the
“sequester,” with a $46 billion reduction through the Sept. 30
end of the current fiscal year.

The cuts – which will deepen in the coming years unless
Congress acts to reverse them – were included in a 2011 law
aimed at reducing the federal government’s yawning deficits and
controlling the national debt.

But top brass have warned Congress that the cuts will erode
military readiness to respond in the future to global tensions,
including over the civil war in Syria and Iran’s nuclear
advances, and as the United States winds down the 11-year-old
war in Afghanistan.

The Pentagon slashed costs across the defense department
before taking the extraordinary step to put civilian employees
on unpaid leave, including cutting back training of troops and
reducing the presence U.S. aircraft carriers in the Gulf region.

Hagel warned in a major policy speech last month last month
that he had ordered a review that could lead to additional
belt-tightening measures, like reducing the number of generals,
paring back the civilian workforce and moving to stem spiraling
costs of new weapons.

The Pentagon is also urging Congress to move forward with a
new round of base closures. Closing domestic military is deeply
unpopular with lawmakers due to the damage such cutbacks can
cause in local economies.

With some of the possible U.S. military options in Syria involving a need for air power, the Pentagon remains concerned about Assad’s ability to shoot down enemy aircraft with surface-to-air missiles, particularly in a sustained campaign.

President Barack Obama has resisted pressure to deepen involvement in Syria’s civil war and has stopped short of even limited steps like arming the anti-government rebels.

If the United States did become more embroiled in Syria – perhaps in reaction to Damascus using chemical weapons – and wanted to wage a large air campaign there it would likely first need to take out Syria’s Russian-made air shield.

While the effectiveness of Syria’s aging air force is unclear, most experts believe its air-defense missile system, considerably upgraded after a 2007 Israeli strike on a suspected nuclear site, remains more potent than any the United States has faced since it bombed Serbian forces in 1999.

“These recent events have not changed our assessment of the sophistication of the Syrian air defense system,” said a senior U.S. official.

That said, the United States does indeed have the power to wipe out Syria’s air defenses.

Syria has little or no protection against hard-to-stop weapons in the U.S. arsenal like B-2 stealth bombers or ship- and submarine-launched cruise missiles. Still, it would require a huge assault involving cruise missiles, and jets possibly flying either from aircraft carriers or bases in neighboring countries.

Israeli jets managed to avoid Syrian defenses twice again in recent days, but the raids were surprise strikes that experts said would have been difficult to defend against. U.S. officials said last week the Israelis did not even enter Syrian airspace in Friday’s bombing, firing missiles instead from the skies over neighboring Lebanon.

NO-FLY ZONE

U.S. jets would be far more at risk if they tried to impose a no-fly zone over Syria or to protect “safe zones” on the ground, which would almost certainly require operations over the country for long periods of time.

“There is a huge difference between conducting a strike and implementing a no-fly zone,” a second U.S. official said.

The Pentagon estimates than Syria has five times more air defenses than those that existed in Libya, where the United States helped establish a no-fly zone in 2011. They are also far more densely packed and sophisticated.

In Libya, there were no Western casualties. But the risks are higher in Syria and it’s unclear whether the war-weary American public – exhausted by the conflicts in Iraq and Afghanistan – would tolerate U.S. casualties.

Before the Syrian civil war began, Western analysts estimated that Assad had around 25 air-defense brigades with some 150 surface-to-air missile launchers.

The first U.S. official noted that Syrian air defenses have been strengthened in recent years. Still, the extent to which its civil war may have degraded those defenses is unclear.

Many of Syria’s anti-aircraft missiles are mobile, which means Assad’s forces could choose to locate them near schools or apartment buildings, hoping U.S. forces might avoid targeting them for fear of causing civilian casualties. The density of the defenses raises the risk of civilian deaths.

The shooting down of a Turkish F4 Phantom reconnaissance jet as it neared the Syrian coast last year demonstrated Syria’s quick-reaction air defenses. But the United States and its allies have options that could make such action safer.

According to one Western defense planner, taking down the entire Syrian system would involve a heavy opening salvo of cruise missiles and then air strikes. The Center for Strategic and International Studies think tank estimates that such an assault would take the combined combat power of at least two U.S. aircraft carriers, although U.S. and allied aircraft could also be based at nearby land bases in Turkey, Jordan and Cyprus.

Obama would be unlikely, however, to go forward with any operation alone, looking to allies like Britain and France to also contribute in the event the United States – despite its extreme reluctance to get involved militarily – found itself forced to take direct action in the Syrian conflict.

Syria is believed to lack any significant defenses against U.S. cruise missiles from reaching their targets or detect and intercept B-2 stealth bombers, which could be used to damage Syrian airfields.

“If you were to fly a B-2 over one of their airfields, you could probably make it so that it would be out of service for awhile,” says Air Vice Marshal Michael Harwood, a retired Royal Air Force officer who was British defense attache to Washington until 2012.

Given the large number of casualties in Syria that are caused by artillery, U.S. forces might need also to strike government artillery if they wanted genuinely to protect any rebel-held “safe zones” on the ground.

General Martin Dempsey, the top U.S. military officer, told the Senate last month: “The safe zone is only safe if you ensure its safety.”

“You have to control the terrain at some distance beyond it in order to do that.”

The Predator, Reaper and Global Hawk-type drones on which Washington has come to rely in Afghanistan – where U.S. air power is virtually unchallenged – would be of little use until Syrian air defenses were neutralized. Those aircraft were not designed to defend themselves from attack.

(Editing by Alistair Bell and Jackie Frank)

In its 83-page annual report to Congress on Chinese military
developments, the Pentagon also cited progress in Beijing’s
effort to develop advanced-technology stealth aircraft and build
an aircraft carrier fleet to project power further offshore.

The report said China’s cyber snooping was a “serious
concern” that pointed to an even greater threat because the
“skills required for these intrusions are similar to those
necessary to conduct computer network attacks.”

“The U.S. government continued to be targeted for (cyber)
intrusions, some of which appear to be attributable directly to
the Chinese government and military,” it said, adding the main
purpose of the hacking was to gain information to benefit
defense industries, military planners and government leaders.

A spokeswoman said it was the first time the annual Pentagon
report had cited Beijing for targeting U.S. defense networks,
but China dismissed the report as groundless.

The U.S. Defense Department had repeatedly “made
irresponsible comments about China’s normal and justified
defense build-up and hyped up the so-called China military
threat,” Chinese Foreign Ministry spokeswoman Hua Chunying said.

“This is not beneficial to U.S.-China mutual trust and
cooperation,” Hua told reporters. “We are firmly opposed to this
and have already made representations to the U.S. side.”

China’s defense build-up was geared towards protecting its
“national independence and sovereignty,” Hua said.

On the accusations of hacking, Hua said: “We firmly oppose
any groundless criticism and hype, because groundless hype and
criticism will only harm bilateral efforts at cooperation and
dialogue.”

Despite concerns over the intrusions, a senior U.S. defense
official said his main worry was the lack of transparency.

“What concerns me is the extent to which China’s military
modernization occurs in the absence of the type of openness and
transparency that others are certainly asking of China,” David
Helvey, deputy assistant secretary of defense for East Asia,
told a Pentagon briefing on the report.

He warned of the “potential implications and consequences of
that lack of transparency on the security calculations of others
in the region.”

The annual China report, which Congress began requesting in
2000, comes amid ongoing tensions in the region due to China’s
military assertiveness and expansive claims of sovereignty over
disputed islands and shoals. Beijing has ongoing territorial
disputes with the Philippines, Japan and other neighbors.

Beijing’s publicly announced defense spending has grown at
an inflation-adjusted pace of nearly 10 percent annually over
the past decade, but Helvey said China’s actual outlays were
thought to be higher.

China announced a 10.7 percent increase in military spending
to $114 billion in March, the Pentagon report said. Publicly
announced defense spending for 2012 was $106 billion, but actual
spending for 2012 could range between $135 billion and $215
billion, it said. U.S. defense spending is more than double
that, at more than $500 billion.

The report highlighted China’s continuing efforts to gain
access to sophisticated military technology to fuel its
modernization program. It cited a laundry list of methods,
including “state-sponsored industrial and technical espionage to
increase the level of technologies and expertise available to
support military research, development and acquisition.”

Dean Cheng, an analyst at the conservative Heritage
Foundation think tank, said he was surprised by the number of
cases of human espionage cited in the report.

“This is a PLA (People’s Liberation Army) that is
extensively, comprehensively modernizing,” Cheng said. “…China
is also comprehensively engaging in espionage.”

China tested its second advanced stealth fighter in as many
years in October 2012, highlighting its “continued ambition to
produce advanced fifth-generation fighter aircraft,” the report
said. Neither aircraft of its stealth aircraft was expected to
achieve effective operational capability before 2018, it said.

Last year also saw China commission its first domestically
produced aircraft carrier. China currently has one aircraft
carrier bought abroad and conducted its first takeoff and
landing from the ship in November.

(Reporting By David Alexander and Phil Stewart, Additional
reporting by Michael Martina in Beijing; Editing by Nick Macfie)

U.S. Secretary of State John Kerry warned North Korea last month that it would be a “huge mistake” to launch the medium-range missiles, but the prospects of a test had put Seoul, Washington and Toyko on edge.

One U.S. official, speaking on condition of anonymity, cautioned that the missiles were still mobile and the fact that they had been moved was no guarantee they would not be set up elsewhere and fired at some point.

“It is premature to celebrate it as good news,” said another U.S. official, Daniel Russel, the senior director for Asian affairs at the National Security Council.

However, a third U.S. official, also speaking on condition of anonymity, said the United States did not believe the missiles had gone to an alternate launch site and that they were now believed to be in a non-operational location.

The Musudan missiles have a range of roughly 3,000 to 3,500 kilometers (1,900 to 2,200 miles). A possible test launch, depending its trajectory, could have dramatically escalated tensions on the Korean peninsula.

North Korea’s move coincided with preparations by President Barack Obama to meet South Korean President Park Guen-hye at the White House on Tuesday, where they will hold talks and have a working lunch followed by a joint news conference.

Pentagon spokesman George Little declined to comment on the status of the North Korean missiles.

“I wouldn’t again comment on intelligence. But what we have seen recently is a ‘provocation pause.’ And we think that’s obviously beneficial to efforts to ensure we have peace and stability on the Korean peninsula,” Little told reporters.

The heightened tensions, including North Korean threats to attack U.S. bases in the Pacific, coincided with U.S.-South Korean military drills that Pyongyang had branded “a rehearsal for invasion.” Those drills ended on April 30.

In a rare show of force during the drills, two nuclear-capable, bat-winged B-2 stealth bombers flew 37 1/2 hours from their U.S. base to drop dummy munitions on a South Korean range, and then returned home.

Asked what may have contributed to Pyonyang’s latest move, Little noted various possibilities, including the fact that, North Korea’s previous cycles of provocation had ended after a while.

He also noted that the Chinese government had made some helpful statements.

“We do think they (China) probably – again I can’t speak for them – they probably heard very loudly from us and from others the need to ratchet it back and lower the temperature,” Little said.

The White House’s Russel told reporters it was too early to determine whether North Korea’s apparent move away from a launch was an encouraging development.

“It’s premature to make a judgment about whether the North Koreans’ provocation cycle is going up, down or zigzagging,” he said. “The decision to launch or not launch missiles, to conduct a provocation or to stand down or defer it, is a decision that rests with the North Koreans.”

(Additional reporting by Steve Holland; editing by Christopher Wilson)

In its 83-page annual report to Congress on Chinese military developments, the U.S. Defense Department also highlighted Beijing’s efforts to develop advanced-technology stealth aircraft and to build an aircraft carrier fleet to project power further offshore.

“What concerns me is the extent to which China’s military modernization occurs in the absence of the type of openness and transparency that others are certainly asking of China,” David Helvey, deputy assistant secretary of defense for East Asia, told a Pentagon briefing on the report.

Helvey welcomed Chinese moves toward greater openness but said there were still many unanswered questions and warned of the “potential implications and consequences of that lack of transparency on the security calculations of others in the region.”

The annual China report, which Congress began requesting in 2000, comes amid tensions in the region due to China’s military assertiveness and expansive claims of sovereignty over disputed islands and shoals.

Beijing’s publicly announced defense spending has grown at an inflation-adjusted pace of nearly 10 percent annually over the past decade, but Helvey acknowledged that China’s actual outlays could be much higher.

China announced a 10.7 percent increase in military spending to $114 billion in March, the Pentagon report said. It said publicly announced defense spending for 2012 was $106 billion, but actual pending for 2012 could range between $135 billion and $215 billion. U.S. defense spending is more than double that, at more than $500 billion.

The report highlighted China’s continuing efforts to gain access to sophisticated military technology to fuel its modernization program. It cited a laundry list of methods, including “state-sponsored industrial and technical espionage to increase the level of technologies and expertise available to support military research, development and acquisition.”

“China continues to engage in activities designed to support military procurement and modernization,” the report said. “These include economic espionage, theft of trade secrets, export control violations, and technology transfer.”

China also relies on acquisitions of key dual-use components, the report said, citing a network of government-affiliated companies and research groups that help it gain access to sensitive technology.

The report referred to two people from Taiwan, for example, who were charged in the United States with trying to pass sensitive defense technology to China by photographing the technology, deleting the images, then taking them to China where the images could be recovered.

(Reporting By David Alexander and Phil Stewart; Editing by Cynthia Osterman and David Brunnstrom)

Defense Secretary Chuck Hagel cautioned that giving weapons to the forces fighting President Bashar al-Assad was only one option being considered by the United States. It carries the risk of arms finding their way into the hands of anti-American extremists among the insurgents, such as the Nusra Front.

But it may be more palatable to many in the United States than direct U.S. military intervention in the conflict, such as carving out a no-fly zone or sending in troops to secure chemical weapons.

Asked whether the Obama administration was rethinking its opposition to arming the rebels, Hagel said, “Yes.”

“You look at and rethink all options. It doesn’t mean you do or you will” choose them, Hagel told a Pentagon news conference.

Obama, speaking in Mexico, said the United States would “look at all options.” But he also signaled no decision would be rushed.

“We want to make sure that we look before we leap and that what we’re doing is actually helpful to the situation, as opposed to making it more deadly or more complex,” Obama said.

Pressure on Obama to act on Syria has grown since the disclosure of U.S. intelligence that Assad’s forces likely used chemical weapons on a small scale, particularly sarin gas.

The Syrian government has also mounted a string of attacks reaching from the capital, Damascus, and the central city of Homs out to the Mediterranean coast, homeland of the Alawite minority sect to which Assad himself belongs.

Forces loyal to Assad stormed the coastal village of Baida on Thursday, killing at least 50 people, including women and children, the Syrian Observatory for Human Rights said.

An Obama administration official, speaking on condition of anonymity, said re-examining the option of arming the rebels was part of a broad look at ways to hasten an end to the conflict, which has cost more than 70,000 lives and forced refugees to flee to U.S. allies Turkey and Jordan.

“Does that mean that they (arms) will be provided? No, it means we’re reviewing all options to see how we can accelerate the transition in Syria,” the official told Reuters.

Most Americans do not want the United States to intervene in Syria’s civil war even if the government there uses chemical weapons, a Reuters/Ipsos poll showed on Wednesday.

British Defence Secretary Philip Hammond, speaking alongside Hagel, noted that his government was constrained by a European Union ban on supplying armaments to the rebels.

“Both of our nations will only do what we legally can do,” Hammond said, adding his government would “look at the situation when that ban expires in a few weeks’ time.”

CHEMICAL WEAPONS

The Obama administration would be extremely reluctant to authorize any intervention involving a large-scale U.S. ground force, and Hagel warned of the risks of Americans being mired in a broad, regional conflict.

The Pentagon has developed plans, however, to potentially deploy troops if needed to secure Syrian chemical weapons sites.

“Any kind of boots-on-the-ground scenario like Iraq is not likely at all,” the U.S. official said.

Indeed, the United States has resisted being dragged militarily into Syria’s conflict and is providing only non-lethal aid to rebels trying to overthrow Assad.

The U.S. official denied that looking again at possibly arming the rebels was being done in response to the intelligence assessment of Syria’s likely use of chemical weapons.

The White House has not specified what evidence it has that Syrian forces used sarin, but U.S. government sources said it included samples of blood from suspected victims, and of soil.

Obama has called any confirmed use of such weapons a “game changer,” but said last week the evidence was only preliminary and that he would not allow himself to be pressured prematurely into deeper intervention in Syria’s two-year-long civil war.

Hammond noted that any evidence of chemical weapons use would need to be at a very high legal threshold to justify military action – particularly with memories still fresh from the Iraq war.

Then, faulty intelligence was used to justify the Iraq invasion in pursuit of nuclear, chemical and biological weapons that turned out not to exist.

Asked whether it might take another chemical weapons attack before the United States and Britain could gather the right kind of evidence, Hammond said it was not that they “necessarily would need” a new attack, even as he acknowledged that evidence of chemical weapons use degraded with time.

“But clearly, if there were future use of chemical agents, that would generate new opportunities for us to establish a clear evidence of use to a legal standard of evidence,” Hammond said.

“There is a very strong view that we have to have very clear, very high-quality evidence before we make plans and act on that evidence.”

Ake Sellstrom, the Swedish scientist leading a U.N. inspection mission charged with investigating allegations of chemical weapons attacks in Syria, met U.S. chemical weapons and regional experts at the State Department on Thursday.

U.N. chief Ban Ki-moon said on Monday the investigators had been gathering and analyzing available information on alleged chemical weapons attacks in Syria but that access to the war-torn country was needed for a “credible and comprehensive inquiry.”

Syria has blocked unconditional and unfettered access by the U.N. mission, which has an advance team in Cyprus ready to deploy to Syria within 24 to 48 hours, and it is unlikely it will gain that type of access any time soon.

(Additional reporting by Matt Spetalnick, Arshad Mohammed and Mark Felsenthal; Editing by Peter Cooney)