Secretary of State John Kerry issued a brief statement on Syria Thursday, saying the U.N. report proves that the Assad regime used the chemical weapons, not the rebel forces. He added that the U.N. Security Council must be prepared to act next week. (The Washington Post)

The U.S.-Russia agreement on Syria’s chemical weapons appeared to be on shaky ground Thursday as Secretary of State John F. Kerry angrily called for U.N. Security Council action to back up the deal, “despite the efforts of some” to deny Syrian government responsibility for last month’s chemical attack outside Damascus.

Appearing in the State Department briefing room to make an unscheduled statement, Kerry said, “We really don’t have time today to pretend that anyone can have their own set of facts approaching the use of chemical weapons in Syria.”

He spoke shortly after Russian President Vladi­mir Putin said his government has “every reason to believe” that the Aug. 21 chemical weapons attack was a “provocation” by rebels seeking to implicate Syrian President Bashar al-Assad.

Putin’s statement, made at a conference northwest of Moscow, echoed comments by Foreign Minister Sergei Lavrov, who just a week ago negotiated an agreement with Kerry to have Syria turn over its chemical arsenal to international monitors for destruction. Assad, who has acquiesced to the agreement, made the same accusation against the rebels in a Fox News interview broadcast Wednesday.

The U.S.-Russia deal is not technically tied to acceptance of responsibility for the attack. But Russia’s renewed emphasis on deflecting blame from the Syrian government has become the public face of an argument taking place behind closed doors at the U.N. Security Council about making Syria’s disarmament commitment binding.

The United States, Britain and France have drafted a resolution that includes consequences — the possible use of military force among them — if Syria reneges on the deal. Without such a resolution, a senior diplomat informed about the U.N. process said, “we are totally naked regarding the consequences of noncompliance by Syria” and open to Russian delay and argument about what to do.

President Obama, who set aside his request for a skeptical Congress to approve unilateral U.S. military action against Syria in favor of the disarmament initiative, said last week that the process would include a U.N. resolution to “verify that the Assad regime keeps its commitments.”

At Security Council meetings this week, Russia has refused even to discuss the draft resolution and has insisted that because Syria “voluntarily” agreed to give up its chemical arsenal, any punishment for noncompliance should be considered only after the fact.

“I believe it is incorrect to speak now about what we will do if the Syrian government fails to fulfill its promises,” Putin said, according to Russia’s Interfax news service. “We currently have no reason to believe that they will not fulfill their obligations. If they don’t, we will consider this issue, but it’s premature to speak about that.”

U.N. inspectors who visited the site of last month’s attack said in a report this week that they found “clear and convincing” evidence that chemicals were used.

“For many weeks, we heard from Russia and from others, ‘Wait for the U.N. report,’ ” Kerry said. Although the inspectors did not assess blame, the United States and its allies, as well as numerous outside experts, have said that evidence clearly points to government culpability.

“Sarin gas was used. Sarin killed,” Kerry said. “The world can decide whether it was used by a regime which has used chemical weapons before — the regime which had the rockets and the weapons — or whether the opposition secretly went into territory they don’t control to fire rockets they don’t have, containing sarin which they don’t possess, to kill their own people.”

His agreement with Lavrov, Kerry said, “clearly said this must be enforceable, it must be done as soon as possible.”

The Security Council, he said, must be prepared to act next week, when nearly 200 heads of state, including Obama, will gather for the annual U.N. General Assembly. Without a council agreement, Syria is likely to become a tense centerpiece of the gathering.

The administration and its allies also hope to use the gathering to showcase the Syrian political opposition, arranging a Friends of Syria meeting with Ahmad al-
Jarba, the newly named head of the opposition coalition.

Although Kerry and Lavrov have pledged to increase momentum toward finding a political solution to the Syrian conflict, they remain at odds over Western insistence that Assad must step down under any negotiated transition government. Russia, Assad’s main diplomatic backer and arms supplier, has said that is an unacceptable precondition to talks between the government and the rebels.

Opposition officials have not yet agreed to attend talks, and Putin echoed remarks by Lavrov that their international patrons should “force” them to do so.

“No matter how difficult it is, we should make them, find points of contact, make them reach agreements,” Putin said. “Then the situation in the country can be stable for some time and maybe even improve.”