U.S. President Barack Obama said on Monday he saw a possible breakthrough in the crisis with Syria after Russia proposed that its ally Damascus hand over its chemical weapons for destruction, which could avert planned U.S. military strikes.
But Obama remained skeptical and pushed ahead to persuade a reluctant and divided Congress to back potential U.S. action, saying the threat of force was needed to press Syria to make concessions.
In an extraordinary day of diplomacy over the war-wracked Middle Eastern country, Russia seized on an apparently throwaway public remark by U.S. Secretary of State John Kerry to fashion a new approach that could save face for all sides.
"It's possible that we can get a breakthrough," Obama told CNN, although there was a risk that it was a further stalling tactic by Syrian President Bashar al-Assad, who has presided over more than two years of civil war.
"We're going to run this to ground," he said. "John Kerry and the rest of my national security team will engage with the Russians and the international community to see, can we arrive at something that is enforceable and serious."
Obama has argued that Assad, fighting to continue his family's four-decade rule, must be punished for what Washington says was a poison gas attack on rebel areas that killed over 1,400 people on August 21.
Human Rights Watch said evidence strongly suggested Syrian government forces were behind the attack.
In Congress, Democratic Senate leader Harry Reid pushed back a Senate test vote on possible U.S. strikes that had been scheduled for Wednesday as lawmakers evaluate the Russian plan.
The vote is still expected this week, and a more contentious vote would later be held in the Republican-controlled House of Representatives.
The dramatic diplomatic twist in weeks of high-tension international wrangling came when Kerry was asked by a reporter during a visit to London whether there was anything Assad's government could do or offer to stop a U.S. military strike.
"Sure. He could turn over every single bit of his chemical weapons to the international community in the next week - turn it over, all of it without delay and allow the full and total accounting. But he isn't about to do it and it can't be done."
The State Department later said Kerry had been making a rhetorical argument about the impossibility of Assad turning over chemical weapons, which Assad denies his forces used.
Less than five hours later, Russian Foreign Minister Sergei Lavrov said he had put what sounded like Kerry's proposal to his visiting Syrian counterpart during talks in Moscow. Walid al-Moualem said Damascus welcomed the Russian initiative - while not spelling out whether Syria would, or even could, comply.
Iran supports Russia's offer to work with Syria to put its chemical weapons under international control, the Iranian foreign ministry said.
Russian President Vladimir Putin has blocked U.N. action against Assad and says Obama would be guilty of unlawful aggression if he launches an attack without U.N. approval.
Lavrov said Russia was also urging Syria to eventually destroy the shemicals weapons it possesses and become a full member of the Organisation for the Prohibition of Chemical Weapons (OPCW).
Kerry later called Lavrov to tell him that while his remarks had been rhetorical and the United States was not going to "play games," if there was a serious proposal, then Washington would take a look at it, a senior U.S. official said.
U.N. Secretary-General Ban Ki-moon took up the same theme, saying that he might ask the Security Council to end its "embarrassing paralysis" over Syria and agree to act.
Asked about Lavrov's proposal, Ban said: "I'm considering urging the Security Council to demand the immediate transfer of Syria's chemical weapons and chemical precursor stocks to places inside Syria where they can be safely stored and destroyed."
Britain and France, permanent members of the Security Council with Russia, China and the United States, both tentatively welcomed the Russian proposal.
WEAPONS BANNED BY 1925 TREATY
U.N. chemical weapons inspectors were in Damascus at the time of the August attack, which Assad and Putin have blamed on rebel forces. Ban said that if the evidence they were able to gather - after lengthy bargaining over their movements with Syrian officials - proved the use of toxins, the world must act.
Syria, which has never signed a global treaty banning the storage of chemical weapons, is believed to have large stocks of sarin, mustard gas and VX nerve agents - the actual use of which is banned by a 1925 treaty to which Damascus is a signatory.
Putin, however, would see major diplomatic advantages to any plan that bolstered Russia's role in brokering international settlements and thwarted strikes in which Obama may have French military support.
Brent crude oil futures sank more than 2% on Monday, as the prospect of a wider war in the Middle East appeared to recede. "This has thrown some sand into the wheels of military preparation in the U.S.," said Michael Lynch of Strategic Energy & Economic Research.
Inside Syria, government forces launched an offensive to wrest back control of a historic Christian town north of Damascus on Monday, activists said. In the past six days, the town of Maaloula has already changed hands three times between Assad's forces and rebels, some of whom are linked to al Qaeda.
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