U.S. Secretary of State John Kerry says a transitional government in Syria would not include president Bashar al-Assad.
Kerry said Thursday in Rome, where he was meeting with Jordanian Foreign Minister Nasser Judeh, that the goal is a political solution agreed to by the Syrian government and those opposed to Mr. Assad.
Kerry says that "clearly means" the Syrian president will not be part of the transitional government.
Syria's main opposition coalition has long demanded that any peace process begin with Mr. Assad and top security officials leaving power.
Earlier this week, Kerry and Russian Foreign Minister Sergei Lavrov announced their hope to convene an international conference later in May to launch Syrian peace talks.
The diplomats say they will try to persuade the two sides to negotiate, based on a plan that calls for a transitional government leading to elections.
Major powers backed that plan in June, but it did not specify whether Mr. Assad could govern Syria in the future.
The United States has called on Mr. Assad to step down, while longtime ally Russia has rejected foreign calls for the president to give up power. However, Russia has also tried to distance itself from the Syrian president's political future.
United Nations-Arab League envoy Lakhdar Brahimi said Wednesday the U.S.-Russian initiative on Syria is "the first hopeful news concerning that unhappy country in a very long time."
He says the initiative is "only a first step," but added that he has "every reason to expect" that all members of the U.N. Security Council will cooperate to carry the process forward.