Representatives of Western and Arab nations have gathered in New York to push for a tough UN resolution on Syria, calling for President Bashar al-Assad to hand power to his deputy.
The UN Security Council on Tuesday evening is debating the draft resolution, with Russia likely to veto any punitive action.
A French official said the draft UN resolution has a "comfortable majority" of support from 10 of the Security Council's 15 members, meaning Russia or China, which has also previously shown support for Assad, would have to use their veto power to stop it.
The draft resolution, seen by the AFP news agency, also calls for the government to put an immediate stop to violence that the UN says has killed thousands of people in the past 10 months.
The draft stresses there will be no foreign military intervention in the conflict and demands that "the Syrian government immediately puts an end to all human rights violations and attacks against those exercising their rights to freedom of expression, peaceful assembly and association".
It calls on Assad to delegate his "full authority to his deputy" and then to form a national unity government leading to "transparent and free elections under Arab and international supervision".
If Assad fails to comply within 15 days, the council would consider "further measures," a reference to a possible move to impose economic or other sanctions.
The text insists it does not compel states "to resort to the use of force, or the threat of force", which a diplomat said was a statement aimed at answering the concerns of Russia and China.
'Path to civil war'
Russia, a veto-wielding Security Council member, has exasperated the West by insisting it will not back a resolution calling on Assad to step down.
A senior Russian diplomat warned on Tuesday that the draft resolution demanding Assad step aside is a "path to civil war".
"The Western draft Security Council resolution on Syria does not lead to a search for compromise," Russia's Deputy Foreign Minister Gennady Gatilov wrote on Twitter.
"Pushing this resolution is a path to civil war."
In October, Moscow vetoed the first council attempt to condemn Syria's crackdown and has shown little sign of budging in its opposition.
Speaking to Al Jazeera, Robert Fisk, Middle East correspondent for the UK's Independent newspaper, said the reason why the Russians were not going along with the resolution was because "they feel conned by the no-fly zone [in Libya]".
"They did not vote against the no-fly-zone over Libya at the Security Council. They didn’t think it meant the overthrow of Gaddafi," he said.
"Since they have their 24-hour port in Tartous, the only 24-hour port they have left in the area, they do not want to lose Syria."
During a trip to Jordan on Tuesday, Ban Ki-moon, the UN secretary-general, called on Assad to stop the killings and said he hoped Security Council members reach a consensus on Syria.
US Secretary of State Hillary Rodham Clinton, and the British and French foreign ministers, were heading to New York to push for the backing of the measure.
"The status quo is unsustainable," Clinton said, saying the Assad government was preventing a peaceful transition and warning that the resulting instability could "spill over throughout the region".
In-depth coverage of escalating violence across Syria
French Foreign Minister Alain Juppe described what is happening in Syria as a "scandal".
Assad "has blood on his hands, so it's not possible that he continues to assume responsibilities," he told French radio Europe-1 on Tuesday, shortly before flying to New York for the meeting.
Juppe ruled out a military intervention saying "things are very different from what happened in Libya".
"For example, in Syria you have communities that are divided and any exterior intervention could lead to a civil war," he said.
Al Jazeera's Rula Amin, reporting from neighbouring Lebanon, said that the violence in Syria continued on Tuesday.
"More than 30 people have been killed by the security forces so far, according to activists in Syria. The government is pushing ahead, trying to firm-up its control all over the country, especially in the rebellious areas, like Homs, Deraa and the suburbs of Damascus."
The bloodshed in Syria spiked on Monday as government forces retook control of the eastern suburbs of Damascus after defected soldiers briefly captured them.
The death toll from Monday's offensive was about 100 people, making it one among the bloodiest days since the uprising began in March, according to the British-based Syrian Observatory for Human Rights and the Local Co-ordination Committees, an opposition group.
Early on Tuesday, government forces moved into the two towns near Damascus still in the hands of the opposition.
"Intense shooting was heard in Zamalka and Arbeen as the tanks advanced," the observatory said, citing its network of sources on the ground.
Security forces made sweeping arrests in the nearby town of Rankus, activists said.