(Reuters) - Defense Secretary Chuck Hagel said on Thursday the U.S.-led air war against Islamic State militants will intensify in the future as Iraqi ground forces improve and become more effective.

Defending the U.S. strategy during a House of Representatives hearing, Hagel said, "As Iraqi forces build strength, the tempo and intensity of our coalition's air campaign will accelerate in tandem."

(Reporting by David Alexander; Editing by Doina Chiacu)