US President-elect Donald Trump urged the government to cancel an order with Boeing Co for a revamped Air Force One, saying costs were out of control.
Air Force One is one of the most prominent symbols of the US presidency. It has been used by US presidents since 1943, according to the company's website.
It was not immediately clear what prompted his complaint about Boeing and the presidential plane on Tuesday, but Trump's transition team said he aimed to send a clear message that he intends to save taxpayers' money after he takes office on January 20.
"Boeing is building a brand new 747 Air Force One for future presidents, but costs are out of control, more than $4bn. Cancel order!" Trump said on Twitter.
The budgeted costs for the Air Force One replacement programme are $2.87bn for the fiscal years 2015 through 2021, according to budget documents.
Trump, who has vowed to use his skills as a businessman to make good deals that benefit American taxpayers, then made a surprise appearance in the lobby of Trump Tower in New York, where he amplified his comments.
"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," he said.
A spokesman for Boeing said the company had no immediate comment. Boeing shares slumped almost one percent after Trump's tweet.
READ MORE: Who is who in Donald Trump's administration
During his unconventional election campaign, Trump complained about the cost of President Barack Obama's use of the presidential aircraft to campaign for his rival Hillary Clinton.
Trump used his own Boeing 757 to campaign around the country, pledging to shake up Washington.
The US air force, which operates the presidential planes, first announced in January 2015 that Boeing's 747-8 would be used to replace the two current planes that transport the US president.
The Air Force awarded Boeing an initial contract worth $25.8m in January this year.
This was to conduct studies on the costs of building the plane with the requirements desired by the White House, including making it possible for the plane to communicate even during a nuclear war, while also looking at lowering costs.