By Warren Strobel and Oliver Holmes
GENEVA/BEIRUT (Reuters) - U.S.-Russian talks on eliminating Syria's chemical weapons program have reached a "pivotal point," a U.S. official said, and both nations said on Friday they wanted to renew efforts to negotiate a peaceful end to the war in Syria.
U.S. Secretary of State John Kerry and Russian Foreign Minister Sergei Lavrov met in Geneva to discuss a Russian proposal under which Syria would sign international treaties banning chemical weapons and hand over its stocks of such weapons to the international community for destruction.
The U.S. official said the two sides were "coming to agreement" on the size of Syria's chemical weapons stockpiles and talks were continuing into Saturday.
U.S. President Barack Obama, after a meeting in Washington with Kuwait's emir, Sheikh Sabah al-Ahmad al-Jaber al-Sabah, reiterated that he will insist any deal on Syria's chemical weapons is "verifiable and enforceable.
In Washington, senior Obama administration officials said the United States does not expect a U.N. Security Council resolution formalising the deal to include potential use of military force due to Russian opposition.
Independently of the United Nations, Obama has threatened the use of force in response to an August 21 chemical weapons attack in Syria that U.S. officials say killed around 1,400 people. But as part of negotiations toward a U.N. resolution, the United States sees no benefit in trying to include the potential use of force.
Russia holds a veto on the Security Council and has previously used it on three occasions when Western powers sought to condemn Assad over the war in Syria. President Vladimir Putin has said the proposal on chemical weapons will only succeed if the United States and its allies rule out the use of force.
The U.S. officials who briefed reporters on condition of anonymity said the U.N. resolution could include a range of consequences should Syria refuse to give up chemical weapons in a verifiable way. Those consequences could include increased sanctions.
After meeting U.N. envoy Lakhdar Brahimi, Lavrov and Kerry said they hoped to meet in New York in about two weeks, around September 28 during the U.N. General Assembly, to see if they could schedule a new international peace conference on Syria.
The talks between teams led by Kerry and Lavrov, which began on Thursday, are at a "pivotal point" and are continuing into Saturday, the U.S. official told reporters in Geneva.
Kerry told a joint news conference: "We are committed to trying to work together, beginning with this initiative on the chemical weapons, in hopes that those efforts could pay off and bring peace and stability to a war-torn part of the world."
He hoped a date might be set for peace talks, but added: "Much ... will depend on the capacity to have success here in the next hours, days, on the subject of the chemical weapons."
Lavrov, voicing regret at the failure of an international accord reached in Geneva last year, said he hoped a "Geneva 2" meeting could lead to a political settlement for Syria.
"We agreed ... to see where we are and see what the Syrian parties think about it and do about it," he said.
Assad's Syrian opponents, many of them disheartened by Obama's failure to make good on threats to launch military strikes in response to the August 21 gas attack, say they see no place for Assad after the war.
However, neither side has been able to finish the fighting, leaving the country's territory divided and its people in misery, including 2 million who are now refugees abroad.
The Syrian opposition coalition, which has struggled to form a coherent response to the Russian proposal, said it would appoint a provisional prime minister on Saturday to raise its international credibility.
The original drive for a political solution to the conflict, dubbed the "Geneva" plan and calling for a transitional government with full power, went nowhere as Assad refused to cede power, and the opposition insisted that he could not be a part of any new political order in the country.
National Coalition member Khaled Khoja said the opposition was still willing to enter into talks with the Assad government if the balance of military power was redressed.
"We are not against Geneva 2, but not under these conditions. The balance of power is not right now. What would restore it is either an air strike or weapons for the Free Syrian Army," Khoja said, referring to more sophisticated anti-tank and anti-aircraft weapons that rebel brigades generally lack.
The United States has blamed Assad's government for the August 21 attack, while Russia and Assad say it was the work of rebel forces.
U.N. Secretary-General Ban Ki-moon said a report by U.N. chemical weapons experts would confirm that poison gas was used in that attack.
Ban also said that Assad "has committed many crimes against humanity," though he did not say whether it was Assad's forces or rebels who used chemical toxins in the August 21 attack.
There is little sign of compromise inside Syria, where sectarian and ethnic hatreds have been deepened by two and a half years of war that has killed over 100,000 people and forced up to a third of the population from their homes.
As the diplomacy continued in Switzerland, Assad's forces were on the offensive around Damascus, opposition activists and residents said. Warplanes and artillery were bombing and shelling, notably in the Barzeh neighbourhood, where activists said there were also clashes on the ground.
"It seems that the government is back to its old routine after the past couple of weeks of taking a defensive posture from a U.S. strike," said one resident of central Damascus, who opposes Assad. She heard jets overhead and artillery in action.
U.N. investigators said Syrian government forces were bombing and shelling hospitals in rebel areas to stop sick and wounded getting treatment, acts which constituted war crimes.
Fighters loyal to Assad purposefully denied people medical care as a "weapon of war", they said in a report.
The Geneva talks were part of a diplomatic push that prompted Obama to put on hold his plans for U.S. air strikes in response to the chemical weapons attack. Moscow's proposal also spared Obama facing a vote in Congress on military action that he had appeared increasingly likely to lose at this stage.
Three-quarters of Americans support efforts to resolve the crisis in Syria through an international agreement to control chemical weapons, according to a new Reuters/Ipsos poll that shows steady opposition to U.S. military action.
In polling of 1,386 Americans conducted Monday through Friday, about 62 percent said the United States should not intervene in Syria, virtually the same percentage as a week earlier.
The United Nations said on Thursday it received a document from Syria on joining the global anti-chemical weapons treaty, a move Assad promised as part of a deal to avoid U.S. air strikes.
The Organisation for the Prohibition of Chemical Weapons (OPCW) said on Friday Syria's deputy foreign minister had contacted it with a request for technical assistance.
But Assad told Russian state television that he would finalise plans to abandon his chemical arsenal only when the United States stopped threatening to attack.
France said a binding U.N. Security Council resolution was needed to police Syria's promise to give up its chemical weapons, insisting the matter cannot be left to the OPCW alone.
The U.S. State Department said Kerry would travel to Jerusalem on Sunday to meet Israeli Prime Minister Benjamin Netanyahu to discuss Middle East peace talks and Syria. He will meet his French and British counterparts in Paris on Monday.
Experts say removing Syria's hundreds of tonnes of chemical weapons, scattered in secret installations, would pose huge technical problems in the middle of a civil war.
(Additional reporting by Stephanie Nebehay and Tom Miles in Geneva, Dmitry Solovyov, Alexei Anishchuk and Thomas Grove in Bishkek, Michael Martina and Ben Blanchard in Beijing, Steve Holland, Roberta Rampton and Jeff Mason in Washington, Louis Charbonneau at the United Nations and William Maclean in Dubai; Writing by Alastair Macdonald and Claudia Parsons; Editing by Giles Elgood and Jim Loney)