Opposition coalition is due to finally decide today whether to join international peace talks next week after Damascus offered a ceasefire plan for the battered city of Aleppo.
But the coalition remains riven by internal divisions, making its attendance at the key talks in Switzerland far from certain despite intense pressure from the West and Arab states.
The talks opening January 22 are aimed at setting up a transitional government to find a way out of the conflict that has killed 130,000 people and made millions homeless since 2011.
The Coalition's general assembly was due to start meeting at an Istanbul hotel Friday, but the talks are now not set to get under way until later Saturday.
Media reports have suggested that the United States and Britain are threatening to withdraw support from the opposition if it fails to send a delegation.
The coalition is beset by rivalries between groups backed by either Qatar or Saudi Arabia, while on the ground, more mainstream Islamist factions are battling al-Qaeda-linked jihadists.
In a surprise move in Moscow on Friday, Syrian Foreign Minister "Walid al-Muallem" presented his Russian counterpart "Sergei Lavrov" with a security plan aimed at halting "all military actions" in the devastated northern city of Aleppo.
Al-Muallem also said the Syrian Government was willing to swap prisoners with the opposition in the first such mass exchange since the conflict erupted, while Lavrov said Damascus was ready to take "a series of humanitarian steps" to improve the delivery of aid.
Syria, Muallem said, would "make every effort to ensure Geneva-2 is a success and meets the aspirations of the Syrian people and the direct orders of President Bashar al-Assad".