U.S. President-elect Donald Trump emerged from a meeting with the CEOs of Boeing and Lockheed Martin on Wednesday and said he was working to lower costs on planes sold to the government, including a new Air Force One fleet and the F-35 fighter jet.

Several three- and four-star generals and admirals attended the meeting, including the F-35 program chief Lieutenant General Christopher Bogdan.

"Trying to get the costs down, costs. Primarily the F-35, we're trying to get the cost down. It's a program that's very very expensive," Trump told reporters after meeting with the aerospace executives and military advisers.

With a current development and acquisition price tag of $379 billion for a total of 2,443 F-35 aircraft -- most of them destined for the Air Force -- the Lockheed Martin-built plane is the most expensive in history, and costs are set to go higher still.

Once servicing, maintenance and other costs for the F-35 are factored in over the aircraft's lifespan through 2070, overall program costs have been projected to rise to as much as $1.5 trillion.

Trump has frequently turned to Twitter to vent his outrage across a range of topics.

On December 6, he blasted Boeing over the possible $4 billion price tag for a replacement Air Force One presidential plane. He also called that project "out of control."

Trump also met with Lockheed CEO Marillyn Hewson and Boeing chief Dennis Muilenburg.

Asked whether he had secured any concessions from Hewson, Trump said: "We're just beginning, it's a dance."

"But we're going to get the costs down and we're going to get it done beautifully."

Boeing's Muilenburg told reporters the meeting with Trump went "great" and said Air Force One would be delivered for less than $4 billion.

"We're going to get it done for less than that, and we're committed to working together to make sure that happens," Muilenburg said.