Russia has now handed over to the US its plans for making Syria’s chemical weapons safe, Russian media say.
Russia announced its plans for placing Syria’s stockpile under international control on Monday and Syria said it welcomed the initiative.
The proposal led US President Barack Obama to put military action against Syria on hold in favour of diplomacy.
Tense negotiations will now follow at the United Nations on the nature of any Security Council resolution.
The UN envoys of the permanent council members – the UK, US, France, China and Russia – are meeting in New York on Wednesday, diplomats say. One said the meeting had been set for 16:00 local time (20:00 GMT).
More than 100,000 people have died since the uprising against President Bashar al-Assad began in 2011.
In other developments:
On the ground, the Syrian army is trying to retake the Christian town of Maaloula. The BBC’s Jeremy Bowen, who has been at the scene, says heavy fighting continued throughout the day. Maaloula was overrun by rebel forces, including members of the al-Qaeda-linked al-Nusra Front, at the weekend
The latest report by UN rights experts, released on Wednesday, says torture and rape are widespread and war crimes are being committed by both sides
UN Secretary General Ban Ki-moon said the UN and its members must share a “heavy burden” for their “collective failure to prevent atrocity crimes in Syria”
Israeli PM Benjamin Netanyahu said Syria had to be stripped of its chemical weapons and that those who had used them must “pay a price”
The UK-based pro-opposition Syrian Observatory for Human Rights said an air strike on a field hospital in Aleppo province had killed at least 11 people
Russian news agencies quoted one Russian source as saying: “We handed over to the Americans a plan to place chemical weapons in Syria under international control. We expect to discuss it in Geneva.”
Russian Foreign Minister Sergei Lavrov and US Secretary of State John Kerry are scheduled to meet in the Swiss city on Thursday to discuss the proposal. They spoke by telephone on Wednesday.
One Russian source told the Itar-Tass news agency the meeting would be bilateral and not involve the UN.
The source added: “It appears that the meeting should start on Thursday and end on Friday, although it is not ruled out that it may last until Saturday.”
No further details of the proposal have been made public.
However, US state department spokeswoman Jen Psaki said that Moscow had so far “put forward ideas” rather than a “lengthy package”.
She also confirmed that Mr Kerry would meet UN-Arab League special envoy on Syria Lakhdar Brahimi in Geneva.
The BBC’s Daniel Sandford in Moscow says there appears to be disagreement between the Russians and the Syrians over whether the weapons should be destroyed.
He says the Syrians are eventually likely to concede the point and allow the arsenal to be dismantled because the Russians will argue that is the only way to gain broader acceptance of the plan.
Syrian Foreign Minister Walid Muallem on Tuesday made the fullest public admission so far that Syria owned a chemical weapons stockpile and gave a clear commitment to the Russian plan.
“We are ready to inform about the location of chemical weapons, halt the production of chemical weapons, and show these objects to representatives of Russia, other states and the United Nations,” he said.
“Our adherence to the Russian initiative has a goal of halting the possession of all chemical weapons.”
The US holds the Syrian government responsible for a chemical weapons attack in Damascus on 21 August, saying it killed 1,429 people. The Syrian government blames the attack on rebels.
Until Tuesday morning, Mr Obama’s government had been lobbying hard for support in Congress for military strikes.
But surveys of politicians had shown he was unlikely to win the planned vote.
In a televised speech from the White House, President Obama said the Russian plan and the regime’s admission that it held chemical weapons were “encouraging signs”.
“It’s too early to tell whether [the Russian plan] will succeed, and any agreement must verify that the Assad regime keeps its commitments,” he said.
Speaking at the Pentagon on Wednesday amid ceremonies to mark the anniversary of the 11 September 2001 attacks, Mr Obama said: “Let us have the wisdom to know that while force is at times necessary, force alone cannot build the world we seek.”
There have already been heated debates at the UN over a possible Security Council resolution on Syria.
The French put forward a draft resolution that would be enforced by Chapter VII of the UN charter, which would in effect sanction the use of force if Syria failed in its obligations.
The draft resolution, obtained by Reuters, sets a 15-day deadline for Syria to provide a full account of the types and location of its chemical weapons.
Correspondents say Moscow opposes any resolution that would be authorised under Chapter VII.
Russia has also said any draft resolution putting the blame on the Syrian government would be unacceptable, and urged a non-binding declaration backing its initiative.
France insists military action remains an option.
President Francois Hollande said on Wednesday: “France will remain in permanent contact with its partners, mobilised to punish the use of chemical weapons by the Syrian regime and to deter them from using them again.”