Russia has said it will support a proposal to form a national unity government, consisting of members of both the government and the opposition.
Kofi Annan’s plan will be discussed at a conference in Geneva on Saturday with the UN Action Group on Syria.
According to Western diplomats, President Assad will not be part of the unity government, although his role is not defined in Annan’s proposals.
Russia has refused to support the removal of Assad as a solution.
"We do not and cannot support any intervention or solutions dictated from abroad" said Foreign Minister Sergei Lavrov.
He added Assad’s future had to be decided through a "Syrian dialogue by the Syrian people themselves".
Turkey meanwhile has strengthened its defences along its border with Syria, deploying rocket launchers and anti-aircraft guns, after one of its fighter jets was shot down by Syria last week.