Secretary of State John Kerry on Friday played down chances of an imminent broad coalition against Islamic State militants, illustrating the difficulty Washington faces winning commitment for a military campaign in the heart of the Middle East. Kerry met Turkish leaders to try to secure support for U.S.-led action against Islamic State, but Ankara's reluctance to play a frontline role highlighted the challenges of building a willing coalition to wage what will likely be a tough offensive. Kerry has been touring the Middle East to build support for President Barack Obama's plan, announced on Wednesday, to strike both sides of the Syrian-Iraqi frontier to defeat Islamic State Sunni fighters, who control swathes of both countries.