U.S. Secretary of State John Kerry is acknowledging that progress will be difficult as he launches a marathon day of talks aimed at ending the Syrian War but is expressing some hope of headway.

With 19 foreign ministers and other senior dignitaries attending, participants say the fact that the talks are happening despite deep divisions among key players are in themselves a sign of success. But Kerry was cautious Friday ahead of a meeting with Sameh Hassan Shoukry, his Egyptian counterpart

"I am hopeful that we can find a way forward," he told reporters, adding: "It is very difficult."

A main focus is what to do about Syrian President Bashar Assad. Saudi Arabia, which is backed by the U.S., wants him quickly ousted, a demand opposed by Iran and Russia.