UN Security Council must act on Syria next week: US Secretary of State John Kerry

The US today called on the UN Security Council to act next week on the use of chemical weapons in Syria, in the wake of a "definitive" report by the world body on the issue.

"I would say to the community of nations, time is short. Let's not spend time debating what we already know. Instead, we have to recognise that the world is watching to see whether we can avert military action and achieve through peaceful means even more than what those military strikes promise," US Secretary of State John Kerry told reporters.

A complete removal of Syria's chemical weapons is possible here, through peaceful means, he said, adding that that will be determined by the resolve of the UN to follow through on the agreement that Russia and the US reached in Geneva.

The agreement clearly said this must be enforceable, it must be done as soon as possible, it must be real, Kerry pointed out.

"We need everyone's help in order to see that the Security Council lives up to its founding values and passes a binding resolution that codifies the strongest possible mechanism to achieve the goal, and to achieve it rapidly. We need to make the Geneva agreement meaningful," Kerry said.

"And to make it meaningful in order to eliminate Syria's CW (chemical weapons) programme and to do it with transparency and with the accountability, the full accountability that is demanded here, it is important that we accomplish the goal in New York and accomplish it as rapidly as possible," he said.

"When we said we know what is true, we meant it. And now before I head to New York for the UN General Assembly, we have a definitive UN report strengthening the case and solidifying our resolve. Now the test comes," he said.

"The Security Council must be prepared to act next week. It is vital for the international community to stand up and speak out in the strongest possible terms about the importance of enforceable action to rid the world of Syria's chemical weapons," Kerry said in a strongly worded statement.

He said the UN report provides "unequivocal" evidence that Syrian President Bashar Assad used sarin gas in August.

Citing ballistic, medical, photographic and other evidence, he said, "every single bit of it confirms what we already knew and what we told America and the world."