Incoming US president Donald Trump called the Lockheed Martin F-35 “very expensive” and vowed to bring down the stealth fighter’s costs after a 21 December meeting with the chief executives of Lockheed Martin and Boeing.

“We’re going to get the costs down and we’re going to get it done beautifully,” Trump told a pool reporter after emerging from a meeting with Marillyn Hewson and Dennis Muilenburg.

Both CEOs met with Trump within weeks after the President-elect attacked both companies on Twitter for costs on key weapons programmes, including the F-35 and the US Air Force’s plan to acquire Boeing 747-8s for the Air Force One presidential transport mission.

After the meeting, Trump reserved most of his ire for the F-35. A week ago, Trump tweeted that the F-35 programme and costs are “out of control”, and he didn’t change his mind after meeting with Hewson.

When asked by the pool reporter what the meeting was about, Trump replied: “Trying to bring costs down — costs. Primarily the F-35, trying to get the costs down. A programme that is very, very expensive.”

Trump’s complaint comes a day after the F-35 joint programme office revealed the Lot 9 price for the F-35A declined by 5% to $102 million, although Lockheed is contemplating challenging that mandated number as too low in the US court system.

Hewson did not respond to the pool reporter’s questions after the meeting, but Lockheed later issued a statement.

“I appreciated the opportunity to discuss the importance of the F-35 programme and the progress we've made in bringing the costs down,” Hewson says in the statement. “The F-35 is a critical programme to our national security, and I conveyed our continued commitment to delivering an affordable aircraft to our US military and our allies.”

Trump also demanded on Twitter that the air force should cancel the Air Force One contract with Boeing, saying costs have spiralled to over $4 billion.

In a separate pool report posted online, Muilenburg said the meeting was productive.

“We’re going to get it one for less than [$4 billion], and we’re committed to working together to make sure that happens,”, Muilenburg says.