Russian President Vladimir Putin said Thursday he was confident but not 100 percent sure that Syria would carry out its commitments to destroy its chemical weapons stockpiles under a Russia-US agreement.

"Will we manage to carry it through? I can't say 100 percent, but all that we have seen recently, in the last few days, inspires confidence that it is possible and that it will be done," Putin said at a meeting of the Valdai international discussion club with Western politicians and journalists in the northwestern Novgorod region.

Putin said Syria was already putting into practice the proposals announced by US Secretary of State John Kerry and Russian Foreign Minister Sergei Lavrov in Geneva on Saturday.

"Will we manage to convince Assad or not? I don't know. But so far everything looks as if Syria has fully agreed with our proposal and is ready to act according to the plan that is being developed by the international community at the United Nations."

Putin, whose government is Syria's most powerful ally, insisted it was not proven who was behind a chemical weapons attack in the Damascus suburb of Ghouta that killed hundreds of people including many children in August.

"It's clear that (chemical) arms were used.... it's just not clear who did it," Putin said. "We have every reason to believe that it was a provocation."

He insisted that only the UN Security Council could discuss whether to use force against Syria.