The UN Security Council voted unanimously on Friday to extend its monitoring mission in Syria for 30 days, Reuters reported.

The decision keeps a key part of international envoy Kofi Annan’s faltering plan to end the 16-month conflict alive.

According to the report, the 15-member council approved a measure put forward by Britain to extend the monitors’ mandate, which had been set to expire on Friday.

Russia, which with China vetoed a resolution on Thursday which would have opened the door to sanctions on the government of Syrian President Bashar al-Assad, dropped its objections to the British proposal after it was broadened to require both government forces and rebel fighters to take steps to halt the violence.

The new resolution states that the council would only consider further extensions to the mission “in the event that the Secretary-General reports and the Security Council confirms the cessation of the use of heavy weapons and a reduction in the level of violence sufficient by all sides” to allow the UNSMIS monitors to implement their mandate.

Both the United States and Britain described the new resolution as a last chance for the observers.

“If over the next 30 days there is a change in that dynamic and those conditions are met then of course the Security Council, on a recommendation by the Secretary-General, will look again at the future of UNSMIS,” Britain’s UN Ambassador Mark Lyall Grant was quoted by Reuters as having told reporters.

“But if the situation does not change then obviously UNSMIS will be withdrawn after 30 days,” he said.

The U.S. Ambassador to the United Nations, Susan Rice, told reporters that Washington had reluctantly acceded to the new resolution, but described it simply as an exit plan for the monitoring teams.

“Today’s vote to extend UNSMIS for a final period of 30 days was not the resolution the United States had hoped to adopt in the first instance. Our strong preference was to adopt the resolution that was regrettably vetoed yesterday,” Rice said, according to Reuters.

She added the extension would “allow (UNSMIS) to withdraw safely and in an orderly fashion.”

Rice said she was skeptical that the Syrian authorities would stop using heavy weapons and the violence would subside enough for the council to consider a renewal of the mission beyond the 30-day extension.

The resolution comes at the end of another bloody week in Syria, during which the fighting between Assad’s forces and rebels escalated and reached the capital Damascus.

On Wednesday, three senior members of Assad’s regime were killed in a suicide bomb attack in the National Security Building in Damascus.

The explosion killed Defense Minister Dawood Rajiha; Deputy Defense Minister Assef Shawkat, Assad’s brother-in-law; Hasan Turkmani, Assad’s security adviser and assistant vice president; and Interior Minister Mohammed Ibrahim al-Shaar.

On Thursday, a rebel attack on the Damascus police headquarters left dozens of security personnel and militiamen loyal to Assad dead or wounded.

Russia’s ambassador to Paris, Alexander Orlov, claimed in an interview on Friday that Assad is ready to give up power but only in a “civilized manner.”

Orlov said that Assad had accepted a transition plan agreed upon by world powers in Geneva, and had named a representative for talks with the opposition. “That is to say, he is accepting to go — but to go in a civilized manner,” he said.

Syria’s Information Ministry rejected Orlov’s comments, saying they were “completely devoid of truth.”