The UN Security Council on Thursday ordered the withdrawal of UN observers in Syria, while Russia called for international powers to set a deadline for government and opposition forces to halt the conflict.
The 15-member Security Council decided not to renew the mandate of the UN Supervision Mission in Syria (UNSMIS) which ends at midnight on Sunday.
The UN originally sent 300 unarmed military observers to Syria in April but its patrols were suspended in June because of the mounting violence and the force was cut back.
"The conditions to continue UNSMIS were not fulfilled," France's UN ambassador Gerard Araud said after a council meeting on the Syria conflict.
"The mission will come to an end at midnight on Sunday," Edmond Mulet, of the UN peacekeeping department told reporters. He added that the 101 observers and 72 civilian staff would leave Syria by Friday of next week.
The Security Council did back plans by UN leader Ban Ki-moon to maintain a political liaison office in Damascus to support the efforts of the successor to UN-Arab League envoy Kofi Annan.
Ban is still negotiating with former Algerian foreign minister Lakhdar Brahimi to take over from Annan, diplomats and officials said.
The Security Council gave a "final" 30 day extension to UNSMIS last month, insisting that it could only go on if the violence eased. But hostilities have worsened and Syrian activists say more than 23,000 people have been killed in the past 17 months. The UN says more than 18,000 have died in the conflict.
Ban wants a political office to be maintained in Syria despite the withdrawal of the observer force.
Araud, president of the Security Council for August, said he had written to Ban giving council backing to the proposal. "There was a consensus to maintain a UN presence at Damascus," Araud told reporters.
Mulet said the liaison office would probably be between 20 and 30 people with political, humanitarian and military experts taking part.
He added that Syria's President Bashar al-Assad had approved setting up the UN office.
Russia, which with China has vetoed three UN resolutions on Syria, called meanwhile for international powers to set a deadline for government and opposition forces to halt the conflict and appoint negotiators.
Russia's UN envoy Vitaly Churkin said UNSMIS should have continued. "We believe that those members of the council who insisted that the UNSMIS can't continue did not really show a commitment to ending hostilities," Churkin told reporters.
Churkin said that the international powers along with other concerned countries, including Saudi Arabia and Iran, should appeal for a halt to the violence and set the deadline.
Russia has called a meeting in New York on Friday of UN ambassadors from the so-called Geneva action group on Syria.
Churkin said they should make the "appeal to all the parties of the Syrian conflict that they end violence as soon as possible, by a certain point in time and that they appoint their authorized representatives in order to negotiate towards a political solution and in particular towards the establishment of a transitional governing body."
Saudi Arabia and Iran would not be at Friday's meeting because they did not take part in the Geneva meeting on June 30, which included the foreign ministers of Russia, the United States, Britain, France and China.
Churkin said the appeal should "call on all the parties to stop violence and also identify the specific time, moment, hour when that should happen."
It was not immediately clear whether the western powers -- still angry at Russia and China for their veto of the UN resolutions -- would attend the New York meeting.
"We're seeking additional information and clarification from the Russians about their proposal," said a US official.
"Our standard for any international meeting is whether it is going to contribute to an end to the violence and a political transition. The question is whether this meeting would advance these goals," the official added.