Senior U.S. Air Force officials said there were opportunities for the incoming administration to cut the cost of the huge F-35 combat jet program, but warned it may be tougher than expected and shouldn’t dilute the advanced plane’s capabilities.

President-elect Donald Trump has said the costs of the F-35 program led by Lockheed Martin Corp LMT, -1.33% are “out of control”, taking aim at the Pentagon’s most expensive program in a series of tweets and speeches.