U.S., Russia agree to framework on Syria chemical weapons

(CNN) -- Russia and the United States announced Saturday that they have reached a groundbreaking deal on a framework to eliminate Syria's chemical weapons, after talks in Switzerland.

U.S. Secretary of State John Kerry and Russian Foreign Minister Sergey Lavrov stood side-by-side as they set out a series of steps the Syria government must follow.

Syria must submit within one week a comprehensive list of its chemical weapons stockpile, Kerry said. International inspectors must be on the ground no later than November, he said.

The framework also envisages the destruction of all Syria's chemical weapons by the middle of next year.

If Syria does not comply with the procedures to eliminate its chemical weapons, the threat of force could be included in a draft U.N. Security Council resolution, U.S. Secretary of State John Kerry said Saturday.

"We've committed to impose measures under Chapter 7 of the United Nations Security Council," he said.

Chapter 7 of the U.N. charter leaves open the ultimate possibility for the Security Council to consider the use of force if Syria fails to comply, but other options will be debated.

Questioned by reporters, Kerry backed off the idea of force, saying he won't specify what the remedy "might be for circumstances we don't even know yet."

He did say that President Barack Obama reserves the right to defend the US and US interests. However, he said, "the president also wants to find a diplomatic solution."

Kerry said the government of Syrian President Bashar al-Assad must allow immediate and "unfettered" access to international inspectors.

But he said there shouldn't be a problem reaching Syria's chemical weapons sites provided the al-Assad regime cooperates, since Syria has moved its chemical weapons into areas where it has tighter control.

This will make it easier for U.N. inspectors to get to them despite the ongoing civil war, he said.

The United States and Russia have reached a shared assessment on the amount and type of chemical weapons possessed by the al-Assad regime, Kerry added.

He praised Russia's President Vladimir Putin and Lavrov for seizing the initiative that resulted in the Geneva talks being called at short notice this week.

News of the deal came after talks extended into a third day.

More talks

On Friday, Kerry and Lavrov also signaled their intent to meet again, on the sidelines of the U.N. General Assembly in New York later this month.

The prospect of yet another round of negotiations in the next few weeks pointed to a potentially bigger endgame for the United States and Russia in the hastily arranged meeting they began on Thursday -- to restart parallel talks on the broader issue of ending the Syrian civil war.

That's not to say all of the many outstanding issues on Syria's chemical weapons have been resolved.

Senior U.S. administration officials told reporters on condition of not being identified the main sticking point was what consequences al-Assad and his government should face over their alleged chemical weapons use.

These officials have no expectations Russia would agree to any U.N. resolution that included authorization for possible military force against Syria. The United States, therefore, will not insist it be included.

That runs counter to Obama's call for the international community to take action, including a potential military strike, for what the United States and allies call a chemical weapons attack by al-Assad's forces last month outside Syria's capital that they say killed more than 1,400 people.

'No change' in U.S. military posture

Obama has threatened to act alone, if necessary, and his administration credits that threat with Russia's surprise proposal last week to have Syria turn over its chemical weapons arsenal to international control.

Outside of the United Nations, however, administration officials insisted they would not take the military threat off the table.

A senior defense official said there has been "no change" in the military's planning or readiness levels and commanders have not been instructed to change their "posture" in any way.

Meanwhile, the Syrian opposition is due to appoint a new interim prime minister Saturday, Khalid Saleh, head of the Syrian National Coalition's media office, told reporters in Istanbul.

As world powers look at the possibility of a future resumption of peace talks in Geneva to resolve the Syrian crisis, Saleh said Friday that any such prospect looks "tremendously different after the use of chemical weapons by the Assad regime."

He added, "While we were previously talking about sitting at the table negotiating, what we are looking for at this point is an enforced transitional agreement where we take the power from the hands of the Assad regime and give it to the Syrian people."

Chemical weapons report expected Monday

The United Nations -- and especially its Security Council, including permanent members the United States, Russia, China, France and Britain -- could play a key role in the international community's response to Syria. And a report by its inspectors on the August 21 chemical weapons attack outside Damascus could be pivotal in guiding where countries come down on the issue.

U.N. Secretary-General Ban Ki-moon is expected to present the report to the Security Council at 11 a.m. ET Monday, three diplomatic sources said. Ban said Friday that he believes it "will be an overwhelming report that chemical weapons were used."

The big questions are by whom and, if that's settled, what the world should do about it.

Al-Assad and other Syrian officials have vehemently denied their forces were responsible, despite assertions by Obama and others to the contrary.

Russia has stood by its longtime ally Syria, challenging the validity of the U.S. claims. At the same time, and as the threat of U.S.-led strikes loomed, Moscow raised its proposal on Syria's chemical weapons stockpiles and working through the U.N. -- this after, time and again, blocking U.N. action involving Syria.

Al-Assad quickly agreed, leading to the talks between Kerry and Lavrov in Geneva that began Thursday. Syria also told the United Nations on Thursday that it has sent the paperwork for joining the Chemical Weapons Convention, which bans such armaments.

The Syrian submission was being reviewed by U.N. lawyers. If deemed sufficient, Secretary-General Ban Ki-moon would register it and Syria would officially be a member state in the convention.

The convention would become legally binding on Syria 30 days after it formally joins, meaning al-Assad's government would have to permit inspections at that time. Another 30 days after that, Syria would have to declare its chemical weapons stockpiles.

Some U.S. intelligence analysts believe it's known where most of Syria's chemical arsenal is stored, according to two U.S. officials familiar with internal discussions. But others say the United States might not be able to verify the location of up to 50% of them.

At the State Department on Friday, spokeswoman Marie Harf said that "verifying, accounting for securing and destroying a large stockpile of chemical weapons takes time," adding that "it's very difficult to do, particularly in an active war zone."

Meanwhile, as the diplomatic efforts continue, those on the ground are caught up in the misery of the Syrian conflict.

The U.N. estimates more than 100,000 people have been killed since the civil war began in 2011, in addition to more than 2 million becoming refugees and over 4 million being displaced within Syria.

CNN's Jim Sciutto, Nick Paton Walsh, Mohammed Jamjoom and Hamdi Alkhshali contributed to this report.