NUCLEAR-SUMMIT/

Dozens of world leaders stood and bowed their heads in a moment of silence honoring Polish President Lech Kaczynski and nearly 100 others who died on Saturday in a plane crash in western Russia. U.S. President Barack Obama remembered the deaths as losses not just for their own country, “a close friend and ally,” but for the world, before making remarks formally opening a gathering of world leaders to discuss nuclear security issues.

“Before I begin, I want to take this moment once again to acknowledge the terrible tragedy that struck the Polish people this weekend. All of us were shocked and deeply saddened by the devastating loss of President Kaczynski, the first lady and so many distinguished civilian and military leaders from your country. This was a loss not just for Poland but for the world,” Obama said.

“As an international community, I know we will all rally around the Polish people who have shown extraordinary strength and resilience throughout their history. So our hearts go out to your people. Our thoughts and prayers are with them. We join them in this time of mourning. And so if everybody is agreeable, I would like to ask for a moment of silence to show that solidarity and to honor those who are lost.”

Kaczynski had been traveling to mark the 70th anniversary of the massacre of more than 20,000 Polish officers by Soviet secret police in the Katyn forest in western Russia when his plane went down on Saturday in thick fog. A total of 96 people died in the crash, including Polish military commanders, top opposition figures and the central bank governor, plunging the country into mourning and bringing forward a presidential vote originally scheduled for October.

Numerous heads of state and government, including Russian President Dmitry Medvedev and German Chancellor Angela Markel are expected to attend the funeral for Kaczynski and his wife on Sunday.  The White House announced later on Tuesday that Obama will also attend.