UNITED NATIONS (Reuters) – U.N. chief Ban Ki-moon and ambassadors from the United States, Britain, France, Russia and China discussed on Thursday “possible diplomatic moves to end” the Syria conflict after U.N. diplomats said mediator Lakhdar Brahimi was determined to quit.

Diplomats, speaking on the condition of anonymity, said on Wednesday that Brahimi wanted to resign from the joint U.N.-Arab League role because he is frustrated with international deadlock over how to end Syria’s two-year war that has killed 70,000.

UNITED NATIONS (Reuters) – Syria urged the United Nations on Tuesday to send scientists to investigate its claim of a chemical attack by rebels in Aleppo, but said it does not trust accusations by the United States, Britain and others that such weapons were used elsewhere in the country.

Syria’s U.N. Ambassador Bashar Ja’afari also accused “armed terrorist groups” of spreading powder from plastic bags – which he described as “probably a kind of chemical material” – among crowds in the northern city of Saraqeb on Monday.

UNITED NATIONS (Reuters) – U.N. chief Ban Ki-moon said on Monday that investigators have been gathering and analyzing available information on alleged chemical weapons attacks in Syria, but access to the war-torn country is needed for a “credible and comprehensive inquiry.”

The issue of possible chemical attacks by President Bashar al-Assad’s government has become a crucial factor that could lead to the United States and other western powers stepping up their involvement in the Syrian civil war.