The UN Security Council met Wednesday amid tense negotiations aimed at persuading Russia to back a tough resolution condemning violence in Syria.

There appeared to be little chance of quickly persuading Russia and China -- both with veto power over resolutions -- to support the proposed measures, which include demanding Syrian President Bashar al-Assad's resignation.

Nevertheless Portuguese Ambassador Jose Filipe Moraes Cabral said he was "encouraged" by the possibility of reaching a compromise as he entered the council chamber.

"Too many things are at stake not to arrive at a reasonable compromise and I hope we do," he told reporters at UN headquarters in New York.

Indian Ambassador Hardeep Singh Puri said that his country is still uneasy about some of the text wording.

"A message has to be addressed to both sides... now that you are dealing with armed opposition," he said. "How do you expect both sides to agree to a recommendation if the precondition is that one side has to step down?"

The ambassadors were expected to hold a two- to three-hour meeting, diplomats told AFP, on condition of anonymity.

The Chinese have also expressed concern over what they see as "regime change" in Damascus, another UN diplomat said.

In Washington, Secretary of State Hillary Clinton said that Security Council member countries had to decide whether they would side with the Syrian people or a "brutal" dictatorship.

"Every member of the council has to make a decision: Whose side are you on?" Clinton told reporters in response to a question about Russian opposition to the current resolution.

"Are you on the side of the Syrian people? Are you on the side of the Arab League?" the chief US diplomat asked.

Clinton spoke after returning from leading a high-powered delegation of top Western diplomats who joined a debate over the draft resolution on Syria at the Security Council on Tuesday.

Moscow's UN envoy, Vitaly Churkin, said Wednesday that Russia will use its veto to block any Security Council resolution on Syria that it deems unacceptable.

"We will not allow a text to be adopted that we consider to be incorrect and will lead to a deepening of the conflict," Churkin was quoted as saying by the RIA Novosti news agency.

Churkin said that Russia was pushing for a text "in which it would be clear that no foreign military intervention will be used in the context of the Syria crisis."

However Churkin also said he was encouraged that the West was now at least listening to its position.

French Foreign Minister Alain Juppe said that Russia was showing a "less negative" attitude towards the resolution.

The resolution proposed by Morocco and backed by the Arab League and Western powers calls for Assad to step down and seeks an end to a military crackdown that has left between 5,000 and 6,000 people dead.