Aircraft manufacturer Boeing on Tuesday responded to President-elect Donald Trump's criticism that its Air Force One work was costing American taxpayers too much.

"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," the company said in a statement Tuesday. "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."

Earlier in the day, Trump said the Boeing order should be canceled, saying it came with a price tag of more than $4 billion and appearing to refer to the building of just one 747 plane.

Boeing is building a brand new 747 Air Force One for future presidents, but costs are out of control, more than $4 billion. Cancel order! — Donald J. Trump (@realDonaldTrump) December 6, 2016

"I think Boeing is doing a little bit of a number," he later told reporters. "We want Boeing to make a lot of money, but not that much money."

The Air Force has said previously there is $1.65 billion earmarked for two new presidential aircraft, according to Politico, while the Government Accountability Office in March priced the project at approximately $3.2 billion.

Politico also points out Trump's tweet came shortly after the Chicago Tribune published comments by Boeing CEO Dennis Muilenburg, in which the executive expressed his concern about Trump's protectionist trade policies. Boeing does a substantial amount of business with China.

Some of the statistics cited by Trump about the project "do not appear to reflect arrangements," White House spokesman Josh Earnest said Tuesday.

Yet as reported by Slate, Todd Harrison – director of the Aerospace Security Project and of defense budget analysis at Washington think tank the Center for Strategic and International Studies – cited budget documents in stating that the cost, seemingly for two Air Force One aircraft, would be around $4 billion.



.@AaronMehta Budget currently shows $2.9B in RDT&E through FY21, does not yet show procurement, will add ~$1B+ https://t.co/M9N8PWWMSU — Todd Harrison (@ToddHarrisonDC) December 6, 2016

Last year's budget showed the procurement funding, see page 3 of this: https://t.co/vrpNFG4fda https://t.co/B2oggQpXKI — Todd Harrison (@ToddHarrisonDC) December 6, 2016

An Air Force statement sent Tuesday afternoon "in response to questions on the cost of a new Air Force One" said the military branch is "still conducting risk reduction activities with Boeing to inform the engineering and manufacturing development contract negotiations that will define the capabilities and cost."