President Barack Obama expressed support Tuesday for U.N. Security Council talks aimed at a diplomatic breakthrough that would allow Syria's government to avoid U.S. missile strikes if it surrenders its chemical weapons arsenal.

But the president was still going to Congress to push his original plan of airstrikes against Bashar Assad's regime in case the new effort fails. Obama also addresses the nation from the White House on Tuesday night.

The Security Council canceled a meeting on a resolution aimed at securing and destroying Syria's chemical weapons stockpiles. The closed consultations had been scheduled for 4 p.m. EDT (2000 GMT) Tuesday.

Council diplomats said Russia asked for the meeting and then withdrew its request. There were no other details.

Obama discussed the plan for U.N. talks with French President Francois Hollande and British Prime Minister David Cameron before meeting with senators who are wary of U.S. military intervention.

A group of senators started preparing a resolution calling for a U.N. team to remove Syria's chemical weapons by a set deadline and allowing U.S. military action if that doesn't happen.

The Obama administration blames Assad's regime for last month's deadly chemical weapons attack outside Damascus and says more than 1,400 people were killed.

The prospects for a diplomatic breakthrough unfolded rapidly as Assad's government accepted a plan advanced by Russia, its closest ally, to turn over its chemical weapons stockpile. Syrian Foreign Minister Walid al-Moallem said his government quickly agreed to the Russian initiative to "thwart U.S. aggression."

Russian Foreign Minister Sergey Lavrov said his country was working with Syria to prepare a detailed plan of action.

France was proposing a Security Council resolution to verify the disarmament.

The path forward was far from certain. Russian President Vladimir Putin, in an interview with Russia Today television, said the plan would only work if the U.S. renounced the use of force against Syria because no country will disarm under threat of military action.

Kerry countered that any deal with Syria to give up its chemical weapons must be enshrined in a binding U.N. Security Council resolution that sets consequences for Syrian non-compliance. He said Russian suggestions that the U.N. endorsement come in the form of a non-binding statement from the rotating president of the Security Council would be unacceptable to the Obama administration.

But White House spokesman Jay Carney acknowledged potential progress. "Before this morning, the Syrian government had never even acknowledged they possessed chemical weapons. Now they have," Carney said on MSNBC.

The first vote in Congress on authorizing the use of military force had been expected Wednesday, but that has been delayed for the alternate proposal.

All sides, including Russia, seemed to welcome the chance to try another solution.

But Kerry said the U.N. approach must not be used as a delaying tactic. And the opposition Syrian National Coalition cast Syria's latest move as a ploy to escape punishment for a crime against humanity.

More than 100,000 people have died in more than two years of Syria's civil war.

Obama on Monday told CBS, "The key is, to paraphrase Ronald Reagan, that we don't just trust, but we also verify. The importance is to make sure that the international community has confidence that these chemical weapons are under control, that they are not being used, that potentially they are removed from Syria and that they are destroyed."

Obama has declined to say what he would do if lawmakers rejected his proposal for military strikes.

The original resolution in the Senate would authorize limited military strikes for up to 90 days and forbids U.S. ground troops in Syria for combat operations. Several Democrats and Republicans announced their opposition Monday.

Democratic Sen. Ed Markey said Obama told senators he was keeping the possibility of military intervention on the table.

Sixty-one percent of Americans want Congress to vote against authorization of military strikes in Syria, according to an Associated Press poll. The poll, taken Sept. 6-8, had a margin of error of plus or minus 3.7 percentage points.

Sen. John McCain, among Congress' most outspoken advocates of intervention in Syria, said he was skeptical of Russia's intentions.

"But to not test it would also be a mistake," he said.

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Associated Press writers Bradley Klapper, Donna Cassata, Julie Pace, David Espo, Alan Fram, Erica Werner and Henry C. Jackson in Washington contributed to this report.