Updated

U.S. Secretary of State Hillary Rodham Clinton says it was "very clear" that all the participants in Saturday's meeting on Syria — including Russia — are on board with a transition plan created by international envoy Kofi Annan.

Clinton spoke Thursday after Russian Foreign Minister Sergey Lavrov said his country would not endorse a call for Syrian President Bashar Assad to give up power. He also denied a claim by a senior U.S. official that Russia was among the backers of a plan for a new Syrian government.

Clinton told reporters that the invitations to Saturday's meeting in Geneva made clear that representatives "were coming on the basis of (Annan's) transition plan."

She said she expects the meeting "to provide an opportunity to make real progress" on that plan.