Trump’s tweet claimed the cost of the new Air Force One fleet would be more than $4 billion. In January, the U.S. Air Force awarded Boeing a preliminary contract worth $25.8 million, Reuters reported. And in a statement Tuesday afternoon, the Air Force said it had budgeted $2.7 billion for research, development, testing and evaluation for the project in 2017.

It’s not clear exactly what Trump’s $4 billion figure referred to, but a Government Accountability Office report published in March estimated that the total cost of replacing both jets would be $3.2 billion, before inflation, for fiscal years 2010 to 2020.

Boeing, whose shares fell slightly after Trump’s tweet, released a statement Tuesday about its work on Air Force One.

“We are currently under contract for $170 million to help determine the capabilities of these complex military aircraft that serve the unique requirements of the President of the United States,” spokesman Todd Blecher said in a statement. “We look forward to working with the U.S. Air Force on subsequent phases of the program allowing us to deliver the best planes for the President at the best value for the American taxpayer.”

Trump’s transition team did not immediately respond to a request for more information.

“The plane is totally out of control,” Trump told reporters in Trump Tower on Tuesday, according to a pool report. “It’s going to be over $4 billion for Air Force One program 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.”

Asked about Trump’s comments Tuesday afternoon, White House spokesman Josh Earnest referred questions about contract details to the Department of Defense. “Some of the statistics that have been, uh, cited, shall we say, don’t appear to reflect the nature of the financial agreement between Boeing and the Department of Defense,” Earnest said, according to a pool report.

Boeing had been planning to replace the current Air Force One fleet—two Boeing 747-200s—with Boeing 747-8 jets, according to its website. The current jets will reach the end of their 30-year lifespan in 2017, the Wall Street Journal reported.

Earlier this year, Trump criticized the age and condition of Air Force One, attacking President Barack Obama’s use of the plane to travel to campaign events for Hillary Clinton.

“Now Air Force One is a very old Boeing 747,” Trump said July, according to the Washington Post. “It sucks up a lot of gas. A lot of fuel. Boy, the fuel bill. You turn on those engines, I can tell you, it’s a lot of money.”

The Air Force did not immediately respond to requests for comment on Tuesday.