The White House doesn't know where President-elect Donald Trump got his figure of more than US$4 billion (NZ$5.6 billion) to replace the Air Force One plane that transports presidents, a spokesman says.
Mr Trump urged the federal government to cancel an order with Boeing Co to develop a new Air Force One, saying costs were more than US$4 billion and "out of control".
"Some of the statistics that have been cited, shall we say, don't appear to reflect the nature of the financial arrangement between Boeing and the Department of Defense," White House spokesman Josh Earnest told reporters.
On Tuesday Donald Trump tweeted: "Boeing is building a brand new 747 Air Force One for future presidents, but costs are out of control, more than US$4 billion. Cancel order!"
Speaking shortly afterward to reporters in New York, Mr Trump said: "The plane is totally out of control. 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," added Mr Trump, who takes office on January 20.
Boeing responded to Mr Trump, saying that it currently only has a US$170 million (NZ$239 million) contract to determine the capabilities of the new presidential aircraft.
"We look forward to working with the US Air Force on subsequent phases of the program allowing us to deliver the best plane for the president at the best value for the American taxpayer," said spokesman Todd Blecher.
The budgeted costs for the Air Force One replacement program are US$2.87 billion for the fiscal years 2015 through 2021, according to budget documents. But the production contract has not yet been awarded to Boeing.
The Air Force first announced in January 2015 that Boeing's 747-8 would be used to replace the two current Air Force planes used to transport the US President.