Turkey and Arab powers kept up pressure on Syria's President Bashar al-Assad to end the crackdown on pro-democracy demonstrators on Friday but longtime ally Russia warned against any foreign intervention.
A deadline set by the Arab League for Syria to sign a deal allowing monitors into the country expired on Friday without any Syrian response.
Arab foreign ministers had said in Cairo on Thursday that unless Syria agreed to let the monitors in to assess progress of an Arab League plan to end eight months of bloodshed, officials would consider imposing sanctions on Saturday.
These could include halting flights, curbing trade and stopping deals with the central bank.
The deadline has already ended, but the Arab League leaves the door open for Syria to reply by the end of the day and if a positive Syrian response comes on Friday, then the Arab League has no objection to agreeing to it, an Arab source said.
Under the November 2 Arab League initiative, Syria agreed to withdraw troops from urban centres, release political prisoners, start a dialogue with the opposition and allow monitors and international media into the country.
But since then hundreds of people, including civilians, security forces and army deserters, have been killed as the unrest which the United Nations says has claimed at least 3,500 lives since March continued.
Turkey on Friday said it could not tolerate any more violence and it was ready to take action with Arab powers if Assad failed to take steps towards ending the repression.
Turkish Foreign Minister Ahmet Davutoglu told a news conference in Ankara he hoped the Syrian government would give a positive response to the Arab League plan.
If it doesn't, there are steps we can take in consultation with the Arab League, he said. I want to say clearly we have no more tolerance for the bloodshed in Syria. The attitude of friendly and fraternal countries on this subject is clear.
The increased pressure followed France's proposal on Thursday for humanitarian corridors to be set up through which food and medicine could be shipped to alleviate civilian suffering.
But some a measure of comfort for Assad came from Russia, China and other countries, who expressed opposition to sanctions
and warned against a foreign military intervention.
At the current stage, what is needed is not resolutions, not sanctions, not pressure, but internal Syrian dialogue, Russian Foreign Ministry spokesman Alexander Lukashevich told a news conference in Moscow.
NO TO INTERVENTION
Moscow has urged the Syrian government to implement reforms but has rejected pressure from opposition groups to join international calls for Assad's resignation. It has accused Western nations of trying to set the stage for armed intervention, as they did in Libya.
Lukashevich repeated those positions, saying Russia supported the Arab League's call for a halt to the violence but that radical opposition groups with foreign support shared the blame. Outside military intervention was absolutely unacceptable.
But he did not shut the door on the French call for humanitarian corridors, saying Moscow needs more information about the proposal.
After a meeting in Moscow on Thursday, diplomats from Russia, China and the other three emerging-market BRIC countries -- Brazil, India and South Africa - also warned against foreign intervention without U.N. backing.
A Western diplomatic source said the French plan, with or without approval from Damascus, could link Syrian civilian centres to the frontiers of Turkey and Lebanon, to the Mediterranean coast or to an airport.
Its aim would enable transport of humanitarian supplies or medicines to a population that is suffering.
French Foreign Minister Alain Juppe said the plan fell short of a military intervention but acknowledged that humanitarian convoys would need armed protection.
Of course...by international observers, but there is no question of military intervention in Syria, he told French radio.
The Arab League suspended Syria's membership two weeks ago, while this week the prime minister of Turkey - a NATO member with the military wherewithal to mount a cross-border operation - told Assad to quit and said he should be mindful of the fate of fallen dictators such as Adolf Hitler, Benito Mussolini and Libya's deposed leader Muammar Gaddafi.
Possible sanctions, which were not intended to affect ordinary Syrians, included suspending flights to Syria, stopping dealings with the central bank, freezing Syrian government bank accounts and halting financial dealings.
They could also decide to stop commercial trade with the government with the exception of strategic commodities so as not to impact the Syrian people, the statement said.
Syria's economy is already reeling from the eight months of unrest, aggravated by U.S. and European sanctions on oil exports and several state businesses.
The Syrian Observatory for Human Rights, a British-based opposition group, said at least 47 people were killed in Syria on Thursday, including 16 soldiers and 17 army deserters, mostly around the city of Homs and Rastan to the north.
Alongside the mainly peaceful protests, armed insurgents have increasingly attacked military targets in recent weeks.
State media have reported the funerals of 34 soldiers and police in the last four days. Since the outbreak of the uprising officials have blamed armed groups for the violence and say 1,100 members of the security forces have been killed.
Assad, 46, seems prepared to fight it out, playing on fears of a sectarian war if Syria's complex ethno-sectarian mosaic shatters and relying on support of senior officials and the military to suppress the protests, inspired by Arab uprisings which toppled the leaders of Tunisia, Egypt, Libya and Yemen.
(Writing by Angus MacSwan)