The Syrian peace talks in Geneva are reported to be deadlocked over the issue of transferring power to a transitional government.
The Syrian government team presented a "declaration of principles" that did not mention transfer of power, and it was rejected by the opposition.
The BBC reports the two sides cannot agree on the future role of President Bashar al-Assad.
However, a Syrian presidential adviser says that talks will continue despite the current stalemate.
UN mediator Lakhdar Brahimi said there was no decision yet on allowing an aid convoy into besieged areas of the city of Homs.