Russia, the United States and powers from Europe and the Middle East outlined a plan Saturday for a political process in Syria leading to elections within two years, but differences remained on key issues such as President Bashar Assad's fate.

A day after gunmen and suicide bombers went on a rampage through Paris, killing at least 129 people, foreign ministers and senior officials from more than a dozen countries agreed to work for a cease-fire in Syria's civil war, but U.S. Secretary of State John Kerry said it would not apply to the Islamic State group.

French President Francois Hollande pledged a "merciless response" to the attacks, which he said had been organized by the extremists. France is part of the U.S.-led coalition carrying out airstrikes against the group in Syria and Iraq.