Donald Trump’s disapproval over costs of Lockheed Martin’s F-35 fighter jets prompted the chief executive of the defense contractor to assure him that the company is committed to driving down the cost of the aircraft. Marillyn Hewson met the president-elect Friday after the latter tweeted that he had asked its rival Boeing to price an upgrade of its F-18 Super Hornet jet that could possibly replace the F-35 jets.

“I had a very good conversation with President-elect Trump this afternoon and assured him that I've heard his message loud and clear about reducing the cost of the F-35,” Hewson said, in a statement posted on Lockheed’s Twitter account. “I gave him my personal commitment to drive the cost down aggressively. I know that President-elect Trump wants the very best capability for our military at the lowest cost for taxpayers, and we’re ready to deliver!”

On Wednesday, Trump met the CEOs of both Boeing and Lockheed Martin in separate meetings in Florida to discuss about Lockheed’s F-35 and Boeing’s 747 Air Force One — both programs he had expressed displeasure over.

Last Monday, Trump blasted the F-35 program over its “out of control” cost in a tweet. He also said that “billions of dollars can and will be saved” on military purchases once he takes office.

According to Lockheed, three variations of over 2,400 F-35s will replace older aircraft used by the Air Force, Navy and Marine Corps. The cost of these combat planes is reportedly estimated to be nearly $400 billion, while operating costs are likely to bring the total costs to above $1 trillion. However, if Trump plans to make any changes or cancel the F-35 program, tens of thousands of jobs the company generates in 45 states will reportedly be affected.

Prior to the F-35s, Boeing’s Air Force One program came under Trump’s scrutiny.

“Well, the plane is totally out of control. It’s going to be over $4 billion for [the] Air Force One program," the 70-year-old said earlier this month. “And I think it’s ridiculous. I think Boeing is doing a little bit of a number. We want Boeing to make a lot of money, but not that much money.”

However, the White House clarified that the Air Force One cost cited by the president-elect did not correlate with the arrangements made between Boeing and the Department of Defense.