U.S. Ambassador Susan Rice was cautious in her remarks after the council session. "We had what I would characterize as sometimes difficult but ultimately useful discussions," she told reporters. "We're still working. This is not done."
Churkin told reporters that Thursday's inconclusive negotiations were "something of a roller-coaster."
"We have a text which we are going to report to our capitals," he said. He declined to provide details but suggested that how Russia might vote remained an open question. He said the fact that the council was getting a revised draft "does not pre-judge anything in any way."
Colombian envoy Nestor Osorio said the council would continue discussions on Friday on the draft, sponsored by Morocco, France, Britain, the United States, Germany, Portugal, Colombia, Togo, Libya, Bahrain, Jordan, Kuwait, Qatar, Saudi Arabia, the United Arab Emirates, Oman and Turkey.
Submitting what some diplomats say is a final draft resolution does not necessarily mean a vote is imminent and further revisions could follow. France said it foresaw a vote on Friday, Saturday or Monday at the latest.
Russia has balked at any language that would open to door to "regime change" in Syria, its most important Middle Eastern ally over the almost half-century Assad's family has ruled it.
Assad has been locked in a struggle with a revolt against his rule for the past 11 months, with at least 5,000 deaths by a United Nations count.
Assad opponents continued their protests in the Syrian city of Hama on Thursday, where the president's father crushed an Islamist uprising 30 years ago. They poured red paint on the ground to symbolize the blood shed then, prompting government troops to close public squares.
Marking the event would have been unthinkable a year ago, but what began as civilian street protests which Assad tried to crush with troops and tanks has evolved in some regions into an armed insurgency that has spread to the gates of Damascus.
The surging violence has stirred Arab and Western calls for international action to stop the bloodshed, but that has been held up by Russian opposition to any steps that would remove Assad or pave the way to foreign intervention.
Russia and China joined forces in October to veto a Western-drafted U.N. resolution that would have condemned Assad's government and threatened possible sanctions.
The latest resolution text includes changes made by Arab and European negotiators to meet some of Russia's concerns. It calls for a "Syrian-led political transition," does not criticize arms sales to Syria and no longer spells out details of what the Arab plan entails, such as Assad giving up power, although it still "fully supports" the plan.
Western envoys said they and the Arabs were trying to assure the Russians the resolution is not aimed at "regime change" in Syria. If Churkin is not satisfied after Friday's U.N. talks, they said, Russian Foreign Minister Sergei Lavrov and U.S. Secretary of State Hillary Clinton might take up the issue in a meeting over the weekend at a security conference in Germany.
Russia says the West exploited what it says was fuzzy wording in a March 2011 Security Council resolution on Libya to turn a mandate to protect civilians in the North African country's uprising into a push to oust the government, backed by NATO air strikes, that led to the overthrow of Muammar Gaddafi.
Moscow has demanded language explicitly ruling out the use of external force in Syria, though the current draft makes clear the council wants the crisis resolved peacefully and the resolution could not be used as the basis for military intervention as in Libya's uprising last year.
The draft does not threaten Syria with sanctions, also rejected by Russia, but includes a vague reference to possible "further measures" in the event of Syrian non-compliance.
Moscow has been a strategic ally of Syria through its decades under Assad dynastic rule and a major arms supplier to Damascus, and so bristles at outsiders trying to dictate internal political change in Damascus.
The Syria resolution came to the global body after the Arab League suspended its monitoring mission in Syria on January 28 as violence surged. Jordan said on Thursday it was pulling its monitors from that mission, joining the departure of Gulf Arab observers, in response to the league's move.
Opposition activists say Assad's forces have stepped up operations around the country after appearing to crush rebels who brought the fight to the outskirts of the capital.
Activists in Hama said fire trucks washed away dye and paint poured on the ground overnight to commemorate the bloodshed of Hafez al-Assad's 1982 assault on the city - center of an Islamist revolt against him - at the cost of over 10,000 lives.
"They want to kill the memory and they do not want us to remember," said an activist in the city, where residents said tanks blocked main squares to prevent demonstrations. "But we will not accept it." Residents said snipers took up positions in the city subsequently.
Sporadic gunfire echoed through the Damascus suburb of Maadamiyyah on Thursday and the body of an army defector was returned to his family mutilated, one activist said. Another reported that Syrian forces killed another activist in that district after raiding his home on Wednesday.
The Syrian state news agency SANA reported funerals of 19 security force personnel killed confronting "terrorist groups," bringing the total of such deaths it has declared in the past few days to about 100.
It was not possible to verify the reports as Syria restricts access for independent media.
(Additional reporting by Joseph Logan and Mariam Karouny in Beirut, Sui-Lee Wee in Beijing, Alissa de Carbonnel in Moscow, Suleiman al-Khalidi and Khaled Oweis in Amman, John Irish in Paris, Arshad Mohammed in Washington; editing by Mark Heinrich and Todd Eastham)