Foreign Minister Laurent Fabius of France arriving at a press conference in Paris on Tuesday.
The Russian blueprint also won backing from China, which has resisted Western calls for military action against Syria but said on Tuesday that it supported Moscow’s vow to avert an American strike following last month’s poison gas attacks outside Damascus.
Hours before President Barack Obama planned to deliver a major national address on the Syrian crisis, the rapid-fire developments elicited skepticism from many regional and international players who questioned the motives behind the Russian gambit and speculated that Moscow’s plan would enable the Syrian authorities to buy time.
Visiting Moscow, Syrian Foreign Minister Walid al-Moallem repeated on Tuesday that the Syrian government accepted the Russian initiative to “uproot U.S. aggression.” But, analysts said, his comment fell short of an unambiguous pledge by Syria to give up its arsenal. It was also unclear if the minister had the authority to speak for President Bashar al-Assad, especially without returning to Damascus for consultations.
Syrian state television quoted Prime Minister Wael al-Halki as saying his government supported Moscow’s initiative “to spare Syrian blood.”
For their part, the rebels battling to overthrow Mr. Assad denounced the Russian proposal as a political maneuver, reflecting a belief that President Vladimir V. Putin was seeking to shield his closest Middle East ally.
In Paris, Foreign Minister Laurent Fabius said the French approach to the Security Council would be made under Chapter 7 of the United Nations Charter, which provides for an array of action, including military, to restore peace and urge the Syrians to accept that their chemical stockpiles would be dismantled.
He also said he expected a “nearly immediate” commitment from the Syrian authorities and added that Russia had information about the chemical weapons stockpile amassed by the Syrian authorities. Mr. Fabius said that he hoped the Security Council would approve a tough resolution after months of efforts by China and Russia to thwart Western action at the United Nations.
The French proposal will call for Syria to allow inspectors from the Organization for the Prohibition of Chemical Weapons to oversee the destruction of chemical weapons in the country and will require that Syria become a member of the organization. It is one of five states that have not signed the Chemical Weapons Convention, an international convention banning the use and stockpiling of chemical arms and the materials required in their production.
“Extremely serious consequences” would be planned for any deviation from the obligations of the resolution, Mr. Fabius said, though he remained cautious about the prospect of the French proposal being adopted. Russia, a firm ally of Mr. Assad and permanent member of the Security Council, has vetoed three Security Council resolutions on Syria since the start of the conflict.
“It is upon the acceptance of these precise conditions that we will judge the credibility of the intentions that were expressed yesterday,” Mr. Fabius said.
France has emerged as the Obama administrations’s leading European ally after the British Parliament voted against involvement in military action in Syria. Earlier, Mr. Fabius said the Russian proposal represented an about-face by Moscow that showed the impact of French and American diplomacy. “We welcome the Russian proposal with interest and caution,” Mr. Fabius told a radio interviewer in Paris. “Our decisiveness has paid off.”Officials in Moscow expressed no small amount of satisfaction that Russia’s plan had — at least for now — averted a military intervention in Syria that Mr. Putin and others have vehemently opposed as a dangerous extension of American meddling in the Middle East.Aleksei K. Pushkov, the chairman of the foreign affairs committee in the State Duma, or lower house of Parliament, said in a posting on Twitter that the proposal “cut the ground from under Obama’s launching of military strikes.”
Mr. Lavrov said he had discussed the proposal with the Americans before announcing it at a hastily arranged briefing on Monday evening. Mr. Obama and Mr. Putin discussed the idea privately on the sidelines of last week’s summit of the Group of 20 nations and Mr. Lavrov discussed it with Secretary of State John Kerry.
Mr. Kerry returned to Washington on Monday after first raising the idea in a dismissive way in London on Monday, making clear that the idea of Mr. Assad giving up Syria’s weapons seemed improbable.
In their conversation, Mr. Kerry told his Russian counterpart, “We’re not going to play games,” according to a senior State Department official.
By Monday night, however, the proposal had gained broad support and Mr. Obama said it was worth exploring. “This proposal is a good way out of a complex situation for all the interested parties,” the chairman of the foreign affairs committee of the upper house of the Russian Parliament, Mikhail V. Margelov, said. Noting the American Senate’s postponement of a vote, he said that Mr. Obama had “saved face among hawks demanding that intervention.”
The Duma, which opened its fall session on Tuesday, announced that it would adopt a resolution supporting the initiative. The Parliament’s chairman, Sergei Y. Naryshkin, cited “the hopefully positive developments” and credited “the principled and unswerving stand of Russia” to avert an intervention.
The hectic developments came as a leading rights group supported conclusions by Western governments that only the government of Mr. Assad could have launched the attack that killed hundreds of people, many of them children.
While Mr. Assad has denied that his forces used toxic agents in the attacks on the morning of Aug. 21, Human Rights Watch in New York said evidence concerning the type of rockets and launchers involved in the strike “suggests that these are weapon systems known and documented to be only in the possession of, and used by, Syrian government armed forces.”
The report identified the delivery systems used on Aug. 21 as a Soviet-era 140-mm rocket “designed to carry and deliver” about five pounds of sarin, and a 330 mm rocket capable of carrying “a large payload of liquid chemical agent.”
On Monday, President Obama tentatively embraced the Russian proposal, adding new uncertainty to his push to win support among allies, the American public and members of Congress for a limited attack.
But the proposal seems freighted with uncertainties relating as much to the tactical considerations behind it as to the practical issues involved in enforcing it at the height of a bloody civil war that has claimed more than 100,000 lives since March 2011.
“If Syria were to put its chemical weapons beyond use under international supervision, clearly that would be a big step forward and should be encouraged,” Prime Minister David Cameron of Britain told Parliament on Monday. “I think we have to be careful, though, to make sure this is not a distraction tactic to discuss something else rather than the problem on the table, but if it is a genuine offer, then it should be genuinely looked at.”
German Chancellor Angela Merkel, facing elections on Sept. 22, seemed noncommital, saying the Russian proposals were “interesting suggestions.”
The sharpest criticism came from opponents of President Assad, who said in a statement in Beirut that the Russian proposal “is a political maneuver and is part of useless procrastination that will only result in more deaths and destruction for the Syrian people,” Agence France-Presse reported.
In Jerusalem, the Israeli government had no immediate comment on the Russian proposal, in line with its policy of trying to keep out of the heated American debate over how to deal with Syria.
Avigdor Lieberman, the former foreign minister of Israel who now chairs the parliamentary Foreign Affairs and Defense Committee and is a political ally of Prime Minister Benjamin Netanyahu, told Israel Radio on Tuesday that it was not yet clear if the Russian proposal entailed the removal of all of Syria’s chemical weapons or supervising them on Syrian territory, and that Israel should not take a stand.
But, like some in the West, Mr. Lieberman expressed skepticism about the initiative, saying that Mr. Assad was “gaining time, and lots of it,” that there was no clarity about the quantity of chemical weapons in Syria’s possession and that Mr. Assad could not be taken at his word.
Israel views its stake in the outcome of the Syrian chemical weapons debate as bigger than most countries: Israeli officials say this as a test case for the upholding of red lines and how President Obama and the international community might deal with Iran’s nuclear weapons program.
Mr. Netanyahu and his aides have long argued that a diplomatic solution to the Iran problem has no chance unless it is coupled with a credible military threat. If the Russian deal on Syria works out in the end to everybody’s satisfaction, some Israelis said it could be seen as a good precedent.
“In Jerusalem they should be happy,” wrote Ron Ben-Yishai, a military affairs analyst on Ynet, a leading Hebrew news site. “It has clearly been proven that a credible American military option can be a successful deterrent. The Iranian context is as clear as the sun, as is the future direction of the joint strategic course of the United States and Israel regarding Tehran.”
But other Israelis were already viewing the developments on Syria as tokens of American weakness.