International mediator Lakhdar Brahimi is expected in the Syrian capital Damascus on Friday to try to broker a brief ceasefire in the war between President Bashar al-Assad and rebels, a U.N. spokesman said.
Brahimi, envoy for the United Nations and the Arab League, has been criss-crossing the region with the aim of convincing Assad's main backers and his foes to support a truce during the Islamic festival of Eid al-Adha next week.
The U.N. spokesman in Damascus, Khaled al-Masri, told Reuters that Brahimi would meet Syrian Foreign Minister Walid al-Moualem on Saturday morning. He did not say whether the envoy would meet Assad himself.
Despite positive words from the different backers of the warring factions, the task of securing even a temporary ceasefire appears daunting in an intensifying conflict in which more than 30,000 people have been killed.
Turkish Foreign Minister Ahmet Davutoglu on Friday called for all sides to observe the three- or four-day ceasefire, a day after saying that the Arab League and Iran, Assad's main backer in the region, supported the proposal.
"It is important that the Syrian regime, which bombards its own people with fighter planes and helicopters, halts these attacks immediately and unconditionally," Davutoglu told reporters in Ankara.
A previous ceasefire in April collapsed after just a few days, with each side blaming the other. Mediator Kofi Annan resigned his post in frustration a few months later. Next week's truce would be self-imposed, with no monitoring.
Lebanese political scientist Hilal Khashan said that Turkey, which supports the uprising, and Iran were probably promoting the ceasefire because "they need to seem like they are doing something".
"I don't think it will work. Neither side trusts the other, and the opposition fears the regime will use the ceasefire to bolster its positions in Aleppo and Idlib," he told Reuters in Beirut.
A rebel group calling itself the Joint Command for Military and Revolution Councils in Syria said in a video statement that it was willing to respect the ceasefire on condition that the Assad government released detainees, particularly women, and lifted the siege of the central city of Homs.
It also called for a halt in air strikes and for access to humanitarian aid - something Assad has in practice denied to several international organisations. It also said the army must not take advantage of the truce to fortify its positions.
The war pitting Assad's troops against a loosely-organised rebel force trying to end his 12 years in power has intensified in recent months.
On Thursday, 240 people were killed across the country in fighting and bombardments, from the capital, Damascus, to the country's commercial centre, Aleppo.