The United Nations voted Saturday to send 300 unarmed ceasefire observers to Syria, but the United States warned it may veto a new mandate for the force because its patience was "exhausted."
In the restive Syrian province of Homs, the first dispatch of UN observers arrived to monitor a shaky ceasefire, as two civilians were said to be among at least 11 people killed across the country, according to the Syrian Observatory for Human Rights.
Under UN Resolution 2043, the military observers will be sent for an initial period of 90 days if UN leader Ban Ki-moon determines it is safe for them to go.
Sporadic clashes between government troops and army deserters have rocked Damascus in recent weeks, ahead of the shaky ceasefire between the government and rebels that went into effect on April 12. Monitors say more than 200 people have been killed in Syria since then.
Russia's UN Ambassador Vitaly Churkin, whose country played a leading role in drawing up the resolution, told the UN Security Council that the measure was of "fundamental importance to push forward the process of the peaceful settlement in Syria."
The United States, however, warned it may prevent the renewal of the mission after the first three months, while urging greater international pressure on the government of President Bashar al-Assad.
Susan Rice, the US ambassador to the United Nations, told AFP that Ban must make a "careful judgment" about conditions in Syria before sending the larger contingent of unarmed monitors there.
"Our patience is exhausted. No one should assume that the United States will agree to renew this mission after 90 days," Rice told the Security Council after it authorized the full mission.
Several western envoys stressed the dangers of sending the observers to Syria, where UN officials say well over 9,000 people have been killed in 13 months of violence.
"It is an unprecedented step to deploy unarmed UN personnel into such a dangerous environment. It is fraught with risk," said Britain's UN Ambassador Mark Lyall Grant.
The small advance team of monitors that is already in Syria, and previously prevented from visiting Homs for "security reasons," was able to tour different districts of the city of the same name, including battered Baba Amr.
Regime forces shelled Baba Amr for a month, leaving hundreds dead, according to monitors, before retaking it from rebels on March 1. Two Western journalists were among those killed.
The visit came as the opposition Syrian National Council claimed that Homs neighborhoods were being pounded, although an activist in the city said the situation was calm.
After the UN vote, Russia called on all sides in the conflict to stop fighting and cooperate with the monitoring team.
But in the town of Qusayr, near the Lebanese border in Homs province, a sniper shot a woman dead, the Britain-based Observatory said.
Ahead of the UN vote, state-media reported authorities released 30 people detained for their alleged role in Syria's anti-regime uprising, but who have "no blood on their hands."
The move takes to nearly 4,000 the number of people the authorities have released since November, SANA reported.
Elsewhere, an "armed terrorist group" blew up a section of an oil pipeline in the Deir Ezzor region of northeast Syria, SANA said.
On Friday, violence persisted on the ground, with at least 46 people killed as thousands of Syrians protested against Assad's regime, according to monitors and activists.
France's UN Ambassador Gerard Araud backed the United States by saying there was "no automatic renewal" of the observer mission, adding that it should only be renewed "if we think it is useful."
Churkin, the Russian envoy, called Rice's remarks "unhelpful."
"Making negative predictions sometimes looks like a prophecy which some people want to be borne out," he told reporters.
The opposition Syrian National Council and the rebel Free Syrian Army hailed the UN Security Council vote, saying it responds to the Syrian people's demands.
"Undoubtedly, the sending of new monitors is a demand of the Syrian people and of the revolutionaries who protest every day," SNC spokesman George Sabra told AFP, welcoming the unanimous council decision.
"But I do not think that 300 monitors will be enough for a country like Syria, where the revolution is affecting every town and village," he added, calling for the mission to be enlarged to make it "more effective.
The rebel army said it remained "committed to the ceasefire" but spokesman Colonel Kassem Saadeddine stressed that "protection of civilians is the responsibility of the international community."
He accused government forces of failing to respect the truce, saying "there are daily bombardments... and tanks are still on the streets" in violation of the peace plan.