Secretary of State John Kerry said on Wednesday that he planned to use his first foreign trip to advance new ideas about how to persuade Syrian President Bashar al-Assad to yield power and agree to a political transition. Though the United States has sought to encourage a negotiated handover of authority to a transitional government, Assad’s determination to cling to power has proved to be a major impediment.

Mr. Kerry stressed the importance of trying to find common ground with the Russians, whose cooperation the Americans have long sought in trying to convince Mr. Assad that he is isolated internationally. Russia has publicly insisted that Mr. Assad’s departure from power should not be a precondition for negotiations between the rebels and the government, and has continued to ship arms and provide financial support to the Assad.