US Secretary of State John Kerry said he had agreed a six-point plan with his Russian counterpart Sergei Lavrov on ridding Syria of chemical weapons within nine months.

Kerry said the regime would now be given a week to submit a comprehensive inventory of its chemical arsenal, rather than the month it had previously sought.

He said he had reached a "shared assessment" with Lavrov on the "size and scope" of the Assad regime's chemical weapons stockpile.

UN weapons inspectors will be on the ground to begin their inspections in Syria no later than November, Kerry said.

A final deadline of July 2014 was set for the destruction of Syria's entire chemical arsenal, Kerry announced.

The deal came after President Obama agreed to abandon his demand for UN resolution on Syria which included the threat of military force if the regime failed to comply.

Russia has consistently rejected any threat of force against its Syrian ally. The US has said its threat of air strikes was instrumental in securing concessions from the Assad regime.

"We stressed to US Secretary of State Kerry that military scenarios should be avoided with respect to Syria," Lavrov said following the talks in Geneva.

Syria has sent documents to the UN to begin the process of signing up to the Chemical Weapons Convention, which Lavrov described as the regime's first move in carrying out its responsibilities under the agreement.

The terms of the framework agreed between Lavrov and Kerry include unfettered access for inspectors, deadlines on Syrian compliance, and in the event of Syria's non-compliance, a referral to the UN security council under Chapter Seven, which covers the use of force.

"If Syria fails to comply with the plan, a response in accordance with UN Charter Chapter 7 will follow," Kerry added.

The six-point plan agreed a rapid assumption of control over Syria's chemical weapons stockpile; the submission within a week of Syria's list of its chemical weapons; extraordinary measures to destroy the weapons, and verify their destruction; unfettered access for inspectors; a committment to destroy all chemical weapons in Syria; and enforcement under a new UN resolution.

Conseqences for Syria in the event of its non-compliance remained a thorny issue for both countries.

"Any violations will be discussed in the UN Security Council ," Kerry said.

"Violations will have to be assessed, examined and verified," countered Lavrov.

The two men will meet again on the sidelines of the UN General Assembly in New York.

UN Secretary General Ban Ki-moon had said the UN weapons inspectors' report would "overwhelmingly" confirm poison gas had been used in Syria.

Speaking at the UN Women's International Forum ahead of the report's publication on Monday, Ban said Syrian President Bashar al-Assad had committed "many crimes against humanity".

Kerry will travel to Israel for talks with prime minister Benjamin Netanyahu, before flying to Paris to meet with the foreign ministers of France, Britain and Saudi Arabia.

In Syria, fierce fighting continued with reports of a night of "exceptionally heavy shelling" in Damascus.