President-elect Donald Trump today met with a number of high-ranking military officials involved in weapons projects today, talking of the need to “try to bring costs down” on the biggest programs, singling out the Lockheed Martin F-35 scheme.

Trump has repeatedly called out the F-35 program’s costs as “out of control.” setting the stage for a potential battle with the major defense contractors who have long gotten away with huge overruns in cost above and beyond the initial estimate.

Trump praised the negotiating skills of the Pentagon brass, saying the negotiations were in the early stages but that he believes they will get the costs down “beautifully.” Since Congress ultimately has the say on paying for the programs, it isn’t clear how much leverage Trump has on the costs.

Trump did, however, meet with top officials at both Lockheed and Boeing, and Boeing CEO Dennis Muilenburg has reportedly promised to cut the costs of the Air Force One program. Exactly how much isn’t clear, though Trump described it as “a tremendous amount.” Boeing’s CEO would only say it’d cost less than $4.2 billion.

It’s not clear that’s even a cut, as previous reports had suggested the final cost in the $4 billion range. The current contract is only for $170 million, and just to “determine the capabilities” of the eventual planes that will someday be built.

Either way that’s a fairly minor program in the grand scheme of things, as the F-35 program for instance is the largest in Pentagon history, already in excess of $400 billion, and with estimates that the all-in costs will be in the $1.4 trillion range.