Russian UN Ambassador Vitaly Churkin has handed over purported evidence that Syrian rebels used sarin gas in an attack.
Churkin said on July 9 that Russian experts were allowed to visit Khan al-Assal, near Aleppo, and gather what Churkin said was firsthand evidence.
Churkin told journalists that a Russian inquiry "established" that rebel forces fired a Bashar-3 missile at Khan al-Assal on March 19, killing 26 people, including 16 government soldiers.
Churkin said the 80-page report he handed to the UN contains results that "clearly indicate" the missile fired at Khan al-Assal had sarin gas and that "there is every reason to believe that it was armed opposition fighters who used chemical weapons in Khan al-Assal."
On July 8, Syria invited Ake Sellstrom, head of the UN fact-finding mission on allegations of chemical weapons use in Syria, and UN disarmament chief Angela Kane to visit Damascus for foreign-minister level talks on conducting a probe of just the Khan al-Assal attack.
The Russian ambassador strongly backed the idea, calling it "a promising process" that hopefully will lead to an investigation.
Britain, France, and the United States have provided UN Secretary-General Ban Ki-moon with information on other alleged chemical weapons attacks in Syria.
Ban has repeatedly said he wants a broader investigation than just Khan al-Assal.
In Washington, White House spokesman Jay Carney said the United States had not seen any evidence to indicate anyone other than the Syrian government "had the ability to use chemical weapons, or has "used chemical weapons."
With reporting by Reuters and AP