Syria's main opposition alliance says it will attend planned peace talks, if a number of conditions are met, BBC News reported.

The Syrian National Coalition is calling for a guarantee that relief agencies will be given access to besieged areas, and political prisoners will be released.

It also says that any conference should result in a political transition.

President Bashar al-Assad's government has rejected any preconditions for the conference in Geneva.

The UN, U.S. and Russia had been trying to convene the meeting by the end of November.

But UN-Arab League envoy Lakhdar Brahimi said last week that the conference would be delayed, although he was still "striving" for a summit by the end of the year.

The Syrian National Coalition reached the agreement after two days of talks in Istanbul.

A statement released by the office of Monzer Azbik, the chief of staff to the coalition's leader, repeated the group's demand that President Assad step down in any transitional government.

It outlined conditions that must be met before the talks, including a guarantee of access for relief agencies.

It comes a day after elders from the Damascus suburb of Qudsaya reportedly managed to negotiate a temporary lifting of a government blockade to allow some food supplies into the area. The suburb has been under siege for a month.

Attempts to set up a "Geneva II" conference to end the Syrian conflict have been continuing for months amid disputes over who should attend and its agenda.

The Syrian government has already agreed to attend peace talks.