Sergei Ryabkov, Russia's deputy foreign minister, said Syria has provided "material evidence" to prove rebels were responsible for the chemical weapons used in last month's attack in Damascus, BBC News reported.
"Just now we were given evidence. We need to analyse it," he told Russian media outlets, without commenting further.
During a trip to Syria, Ryabkov said the chemical weapons report by the United Nations -- which discovered the use of nerve agent Sarin in the deadly August attack -- was politicized.
"The basis of information upon which it is built is not sufficient, and in any case we would need to learn and know more on what happened beyond and above that incident of 21 August," he said.
"We are disappointed, to put it mildly, about the approach taken by the UN secretariat and the UN inspectors, who prepared the report selectively and incompletely."
French Foreign Minister Laurent Fabius defended the report and said Russia's reaction to the report's conclusion was surprising.
"Nobody can question the objectivity of the people appointed by the UN," he said.
Ake Sellstrom, the UN's chief investigator, said Russia was criticizing the process of the report, not the content in it. Sellstrom did not place blame for the Damascus attack and suggested finding and stockpiling Syria's chemical weapons would be "stressful work," although "doable."
Syria recently made a disarmament deal with the U.S. and Russia, promising to hand over all of their chemical weapons by next year -- a deal U.S. Secretary of State John Kerry referred to as "ambitious."
After the U.S. claimed Syrian President Bashar Assad ordered the chemical weapons attack on Aug. 21 that left 1,300 people dead, President Barack Obama threatened a strike on Syria and began a series of talks and investigations into the attack.
