US Secretary of State John Kerry is calling for Syria's opposition to attend peace talks in Geneva next week.
The main political opposition movement, the Syrian National Coalition, was meeting in Istanbul on Friday to vote on whether to go to the talks.
Opposition fighters in the Syrian city of Aleppo in October 2013. Photo: AFP
Mr Kerry stressed the aim of the so-called Geneva II talks was to begin the process of setting up a transitional government to end the war in Syria.
It is the only way to bring about an end to the civil war that has triggered one of the planet's most severe humanitarian disasters, and which has created the seeding grounds for extremism."
Mr Kerry stressed that only people "agreed by both the opposition and the regime" would be considered for a role in any future transitional government.
The BBC reports Syria's opposition is deeply divided. Although the National Coalition is widely regarded abroad as the legitimate representative of the Syrian people, there are several other opposition alliances and powerful Islamist rebel groups which refuse to recognise its authority.
The three-year conflict has claimed the lives of more than 100,000 people. An estimated two million people have fled the country and some 6.5 million have been internally displaced.
