GENEVA—The U.S. and Russia agreed Saturday on a broad framework for Syria to destroy its stockpile of chemical weapons by the first half of next year.
Moscow and Washington are demanding that Syrian President Bashar al-Assad provide a complete declaration of his country's chemical weapons stockpiles to the Hague-based Organization for the Prohibition of Chemical Weapons by next Friday.
The U.S.-Russian agreement calls for inspectors from the chemical-weapons organization to be granted "immediate and unfettered" access to Syrian chemical-weapons sites, which the U.S. believes number as many as 45.
Under the framework, the organization would complete its initial on-site inspections by November, and would destroy much of Syria's production equipment.
Russian and American diplomats said they hoped to completely dismantle Syria's chemical weapons infrastructure by the first half of 2014. They said the destruction of chemicals, mixing agents, munitions and some delivery systems would take place both inside Syria as well as in third countries, over that time.
U.S. intelligence officials believe Syria has about 1,000 tons of mustard gas and sarin and VX nerve agents in its arsenal.
"If we can make this framework a success, we save lives in the region and lay the groundwork for more cooperation" between Moscow and Washington, Secretary of State John Kerry said Saturday after three days of negotiations with his Russian counterpart, Sergey Lavrov. "There is no military solution in Syria. It has to happen at the negotiating table."
Mr. Lavrov said at a joint press conference that the framework was reached by "consensus and compromise." He described them as "Russian and American proposals."
Both diplomats were accompanied in Geneva by large staffs with expertise in chemical weapons and disarmament procedures.
The two diplomats also said Saturday they would seek a U.N. Security Council resolution that could authorize sanctions — short of military action — if Syria failed to comply with the plan.
The resolution would allow for punitive measures for noncompliance, but stop short of military action, if the 16-nation Security Council approves them. The U.S. and Russia are two of the five permanent Security Council members with a veto. The others are Britain, China, and France.
U.S. administration officials had said that President Barack Obama was open to a Security Council resolution that didn't include military force as a punishment if Syria didn't follow through on promises regarding the weapons. While Russia would be all but certain to veto any measure with such a penalty, Obama's willingness to concede the point — after threatening a U.S.-led military strike with or without approval by the U.S. Congress — provided a step forward.
"I have no doubt that the combination of the threat of force and the willingness to pursue diplomacy helped to bring us to this moment," Mr. Kerry said Saturday
Mr. Kerry said the two sides had agreed on grounds under which they might request a Security Council "Chapter 7" resolution at the United Nations, which is a measure that could include military and nonmilitary sanctions.
But Mr. Lavrov, who said the agreement was "based on consensus and compromise and professionalism," indicated there would be limits to using a Chapter 7 resolution, which Russia would almost certainly veto if it specifically authorized a military strike such as what U.S. President Barack Obama has threatened.
"Any violations of procedures ... would be looked at by the Security Council and if they are approved, the Security Council would take the required measures, concrete measures," Mr. Lavrov said. "Nothing is said about the use of force or about any automatic sanctions. All violations should be approved by the Security Council," he added.
Mr. Kerry said the pair and their teams of experts had come to agreement on the exact size of Syria's weapons stockpile, which had been a sticking point before their meetings in Geneva. But in marathon sessions into early morning hours, the U.S. and Russia succeeded in narrowing their differences.
The agreement over the Russian proposal to inventory, isolate and eventually destroy Syria's chemical weapons stocks comes as the Obama administration warns that there is a limited timetable for a diplomatic resolution of the weapons issue.
Administration officials have said that Washington would retain the authority to order U.S. airstrikes against Syria. Mr. Obama himself said that any agreement to remove Syria's chemical weapons stockpile "needs to be verifiable and enforceable."
The diplomacy came as U.N. inspectors prepared this weekend to turn in a report on the Aug. 21 attacks on neighborhoods on the outskirts of Damascus. Two U.N. diplomats, speaking on condition of anonymity because the time was not yet final, said Friday night that Secretary-General Ban Ki-moon was expected to brief the Security Council about the report on Monday morning.
Mr. Ban said Friday that he expected "an overwhelming report" that chemical weapons were indeed in the Aug. 21 attacks. Mr. Obama called for a limited military strike against Mr. Assad's forces in response, then deferred seeking congressional approval to consider the Russian proposal.
The stakes have been especially high in Geneva, because the negotiations between the U.S. and Russia on securing Syria's chemical weapons also are considered key to breaking the international stalemate that has so far blocked a resumption of peace talks to end the Syrian civil war, now in its third year.
Messrs. Kerry and Lavrov also met Friday with U.N.-Arab League envoy Lakhdar Brahimi about the potential for a new peace conference in the Swiss city and said the three would talk further around Sept. 28 on the sidelines of the annual U.N. General Assembly meetings in New York.
"We are committed to try to work together, beginning with this initiative on the chemical weapons, in hopes that those efforts could pay off and bring peace and stability to a war-torn part of the world," Mr. Kerry said.
Mr. Kerry said the chances for a second peace conference in Geneva would require success first with the chemical-weapons talks.
Mr. Kerry planned to travel to Jerusalem on Sunday to discuss the situation in Syria with Israeli Prime Minister Benjamin Netanyahu. He will then go to Paris to see French Foreign Minister Laurent Fabius and British Foreign Secretary William Hague on Monday about the Syrian war. In Paris, he will meet separately with Saudi Foreign Minister Saud al-Faisal.
This article originally appeared in The Washington Post. The Associated Press contributed to this article.