BEIRUT (AP) -- Syria's main opposition group in exile was "deeply skeptical" Friday about Damascus signing an international treaty banning the production and use of chemical weapons, saying a U.N. resolution was needed to enforce compliance.
Syrian President Bashar Assad told Russian TV that his government would start submitting data on its chemical weapons stockpile a month after signing the convention.
His ambassador to the United Nations said that as of Thursday, Syria had become a full member of the treaty, which requires destruction of all chemical weapons.
"This gesture comes as too little, too late to save civilians from the regime's murderous intent," said the main Western-backed Syrian opposition group, the Syrian National Council.
"It is clearly an attempt to evade international action as well as accountability in front of the Syrian people," it said.
It said the regime must not be allowed to use diplomacy "to indefinitely stall international action while it continues its policy of widespread violence against civilians."
Syria's acceptance of a Russian proposal to relinquish its chemical weapons stockpile has -- for now -- averted a U.S. military strike in response to the alleged chemical weapons attack that killed hundreds near Damascus on Aug. 21.
The U.S. accuses Assad's government of being responsible for the attack in the suburb of Ghouta, saying 1,429 people were killed; others estimated a lower death toll.
Assad has denied responsibility, blaming the rebels and accusing Washington of spreading lies without evidence to justify a military strike.
U.N. Secretary-General Ban Ki-moon said he believes there will be "an overwhelming report" from the world body's inspectors that chemical weapons were used in the attack, but he did not say who was responsible. Under the mandate for the inspectors, the team was to determine whether or not chemical agents were used and if so, which agent.
The chief chemical weapons inspector, Ake Sellstrom, told The Associated Press that he has completed his report and will deliver it to Ban in New York this weekend.
Ban also said the Assad's regime "has committed many crimes against humanity."
"Therefore, I'm sure that there will be surely the process of accountability when everything is over," Ban said in remarks shown on U.N. television.
Fighting in the civil war continued. Activists said government troops battled for the ancient Christian village of Maaloula, northeast of the capital of Damascus; regime warplanes bombed rebel positions in the southern province of Daraa and in the eastern oil-rich province of Deir el-Zour; and both sides clashed in Barzeh, on the edge of Damascus.
Russian President Vladimir Putin praised Syria's joining of the Chemical Weapons Convention, telling an international security meeting in Kyrgyzstan that the move proved Damascus' "serious intentions." The summit was dominated by Russia, China and Iran, all Assad allies.
Syria's opposition said it was "deeply skeptical," and rebel commanders accused Assad of moving the chemical weapons to make tracking them more difficult.
Qassem Saadeddine, a former Syrian army colonel and spokesman for the rebels' Supreme Military Council, said the Syrian leadership has spread its chemical weapons over several dozen locations.
Saadeddine also accused Syria of sending some of the weapons to Hezbollah in Lebanon and to Iraq -- both close to the regime. He declined to give the source of his information.
"The chemical weapons convention requires a state to act in good faith," the SNC said. "Considering the regime's actions, this is not something the Syrian people can afford to grant the regime."
France has proposed a draft resolution that demands the weapons be put under international control and dismantled. Submitted under Chapter 7 of the U.N. charter, which makes it enforceable militarily, it warns of "very serious consequences" if Syria does not comply.
Russia has rejected any resolution under Chapter 7 and proposed a weaker presidential statement -- a move rejected by the U.S., Britain and France.
U.S. and Russian chemical weapons experts met in Geneva to haggle over the technical details.
The SNC urged the U.S. to keep the threat of force on the table, saying a U.N. resolution must be enforceable under Chapter 7.
U.S. Secretary of State John Kerry and Russian Foreign Minister Sergey Lavrov met in Geneva with U.N.-Arab League envoy Lakhdar Brahimi to examine political developments and plot a new international conference to support the creation of a transitional government for Syria.
Also Friday, Human Rights Watch accused Syrian government forces and pro-regime militias of carrying out mass killings of at least 248 people in two predominantly Sunni Muslim towns along the Mediterranean in May.