The US President, Barack Obama, has welcomed the deal reached on Saturday to strip Syria of chemical weapons, but said much remains to be done.

In a statement, Obama 'warned' Damascus to comply with the accord and said that if the regime of Syria's President Bashar al-Assad does not live up to the deal Washington reached with Syria's ally Russia, "the United States remains prepared to act".

Obama said the accord was made possible "in part" by what he called his credible threat to use force against Syria as punishment for its alleged use of chemical weapons against civilians last month that according to American estimates killed about 1,400 people.

"We now have the opportunity to achieve our objectives through diplomacy" he said.

Syria has a week to declare its chemical weapons and must allow international inspections, the US Secretary of State John Kerry said after talks with his Russian counterpart Sergey Lavrov.

The demands are part of a six-point plan aimed at eliminating Syria's stockpiles by mid-2014, which was agreed by the US and Russia after three days of negotiations in Geneva.

Speaking at a news conference with Lavrov, Kerry said that weapons inspectors should be on the ground in Syria by November with the goal of eliminating President al-Assad's stockpiles by mid-2014.

The agreement did not mention any threat of force if Syria failed to comply, instead stating that the regime would become the subject of an as-yet unwritten UN Security Council resolution.

Efforts earlier this week to draft a resolution were complicated by Russia and the West's differences on the threat of force.

Al Jazeera's diplomatic editor James Bays said that the lack of agreement on the content of a resolution would be troubling to some nations, and there would be differing opinions on what constituted a violation.

"We certainly know that the UK-French plan was to come up with a very tough resolution ... that would include all of this deal but it would automatically trigger the use of force if there was a violation."

There has been no formal reaction from the Syrian regime.

Opposition response

The agreement was criticized by General Salim Idris of the Free Syrian Army, the main armed opposition group.

"We cannot accept any part of this initiative," he said. "The FSA will work towards toppling Assad and does not care about US-Russia deals. I and my brothers in arms will continue to fight until the regime falls."

He added that the FSA was "frustrated, and feels betrayed by the international community. It has no faith the UN will ever support it".

Al Jazeera's Anita McNaught, reporting from Antakya in Turkey, said that Idris was obviously angered by the deal.

"You heard him say it was a device to buy time for the Syrian regime and the Russians were aiding and abetting the process. And he feels - and he's said this before - that it misses the main point: that more than 100,000 Syrians have been killed by conventional means, and that war continues.

"The initiative doesn't do anything to address that, nor the country's rapidly increasing refugee crisis."

The US accuses the Assad regime of killing 1,429 people in a chemical assault in Damascus suburbs on August 21. Assad denies involvement in the attack. The US at first pushed for military action against Assad, but later agreed to try to find a diplomatic solution after the intervention of Assad's ally, Russia.

The US-Russia deal could also pave the way for the resumption of peace talks to end the war, now in its third year. More than 100,000 people have been killed, and millions have fled either to other countries or to safer areas within Syria.

PHOTO CAPTION

US President Barack Obama speaks during a cabinet meeting in the Cabinet Room of the White House in Washington, DC, on September 12, 2013.

Aljazeera