The UN's envoy for Syria has said there is international agreement that a transitional government should be set up in order to end the fighting.
Kofi Annan said an international conference in Geneva had agreed there should be a "transitional government body with full executive powers".
This could include both members of the government and opposition.
Saturday's "working group" conference was attended by both Western powers and Russia and China.
Mr Annan also called for an immediate ceasefire and adherence to the UN's six-point peace plan.
He said there should be access to Syria for humanitarian organisations and media.
Some 15,800 people have died in the 16-month uprising against the rule of Syrian President Bashar al-Assad, activists say.
More than 180 people are said to have been killed on Friday alone as government forces reportedly shelled a suburb of the capital Damascus and the restive central city of Homs.
On Saturday, activists and witnesses said many residents were fleeing the Damascus suburb of Douma, which has come under sustained assault from government forces.