Members of the United Nations Security Council have failed to reach agreement on a draft resolution that would authorise a UN observer mission to Syria, with Russia registering objections to its contents.
After failing to come to an agreement on the resolution during lengthy debates on Friday, members of the council were expected to vote on a revised resolution on Saturday.
The United States called for the vote at 15:00 GMT on Saturday, but Vitaly Churkin, Russia's ambassador to the UN, said he was not "completely satisfied", describing negotiations as "rather difficult".
Russia and China have twice used their veto rights as permanent members to block a tougher stance by the council against the Syrian government, but both countries have expressed support for a peace plan devised by Kofi Annan, the joint UN-Arab League on Syria.
The two countries had earlier submitted alternative draft resolutions for the vote by the 15-member body on the proposed deployment of 30 observers to Syria to monitor a ceasefire implemented as part of a UN-Arab League peace plan.
The United States-proposed resolution, backed by Britain, France, Germany, and others, registered a draft resolution that demanded "full, unimpeded, and immediate freedom of movement" for an observer mission.
It warned of "further measures" if Assad's government did not "implement visibly" the commitments made under Annan's peace plan.
'Boots on the ground'
Russia, which has stood by Damascus throughout its crackdown on an anti-government uprising, later distributed another version of the resolution, taking out the demand for "unimpeded" access and any reference to measures that could be taken if the Syrian government was deemed to be in non-compliance with the resolution.
It also took out condemnation of alleged human rights abuses in Syria.
Churkin said his country favoured a brief resolution that would get "some boots on the ground" in the form of the advance observer mission, with the mandate of the full mission to be debated later.
Annan has urged the council to call on Assad to implement all portions of his six-point peace plan that has nominally been accepted by the government and parts of the opposition.
Annan's plan includes, among other things, the requirement that troops and heavy weapons be withdrawn from Syria's cities in order to curb the government crackdown.
The rival resolutions authorise the deployment of up to 30 unarmed military observers. The UN eventually wants at least 200 monitors in the country where it says more than 9,000 people have been killed in the past 13 months.
Observers 'standing by'
Ahmed Fawzi, a spokesman for Annan, said on Friday that the team of observers was "standing by", and that a ceasefire put in place under the plan was largely holding.
Protests in the wake of that ceasefire broke out across the country, although activists said several protesters had been killed when government forces fired their guns in the air.
Fawzi told Al Jazeera on Friday that scattered reports of violence in Syria did not mean the ceasefire was failing and called on both sides to exercise restraint. He said that while there were reports of "skirmishes ... the fact remains that heavy shelling ... has died down".
The continued presence of government troops and armoured vehicles in cities and other civilian areas, a violation of one of the six key points in Annan's peace plan, was extremely concerning, Fawzi said, but more important was a halt to the killing.
Demonstrations began across the country on Friday afternoon as Syrian forces tightened security in public squares and outside mosques.
At least one protester was killed when a demonstration tried to reach central Hama, the Syrian Observatory for Human Rights, a UK-based organisation, said. Other activists said two people had been shot dead at an army checkpoint.
An activist in a town near the Turkish border told Al Jazeera's Anita McNaught, reporting from Turkey, that pro-government armed groups known as shabiha had personally threatened to kill residents who protested on Friday.
Activist video posted on YouTube apparently showed protesters throwing rocks at security forces in Aleppo, Syria's second-largest city, and gunfire could be heard.