WASHINGTON (Reuters) - The United States and 17 other countries on Thursday will call on Hamas to release hostages as a pathway to end the crisis in Gaza, a senior U.S. administration official said.

"We call for the immediate release of all hostages held by Hamas in Gaza now for over 200 days," a statement released by the countries will say, according to the official, who called the joint statement an extraordinary display of unanimity.

(Reporting by Steve Holland and Doina Chiacu; Editing by Chizu Nomiyama)