NEW YORK: US President-elect Donald Trump said on Tuesday costs for a new Air Force One - one of the most prominent symbols of the US presidency - were out of control, and urged the government to cancel a contract with Boeing Co for the jet.
Trump, who takes office on January 20, griped during his unconventional election campaign about the cost of President Barack Obama's use of the presidential aircraft to campaign for his rival, Hillary Clinton.
It was not immediately clear what prompted his complaint about Boeing and the presidential plane, but his transition team said that he aimed to send a clear message he intends to save taxpayers' money.
"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!" Trump said in a morning Twitter message.
It was not clear what his source of information was for the cost.
The budgeted costs for the Air Force One replacement programme are $2.87 billion for the fiscal years 2015 through 2021, according to budget documents.
Shortly after his Tweet, Trump made a surprise appearance in Trump Tower in New York before a group of reporters to amplify 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 dipped after Trump's tweet and were down 0.7 per cent in morning trading.
Shares of several other major defence contractors were also lower.
A wealthy real estate developer, 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 $25.8 million 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.
Trump's transition team said that his comments about the plane reflected the president-elect's desire to keep down costs across the board, and so save taxpayers' money.
Boeing officials were caught off guard by Trump's comments since the company is simply meeting requirements mapped out by the Air Force in consultation with the White House, said defence consultant Loren Thompson, who has close ties to Boeing and other companies.
Thompson said the cost of the contract is high because of the plane's unique security requirements and communications equipment.
"Air Force One has unique mission requirements, including possibly having to operate in a nuclear war," Thompson said.
"Of course it's not like buying a vanilla Boeing jumbo jet."
US presidents have used Boeing planes since 1943, according to the company's website.
The 747-8 planes, 240 feet long (73 meters) long with a wing span of 224 feet (68 meters), can fly direct from Washington to Hong Kong, 1,000 miles (1,600 km) farther than the current Air Force One.
In a September 2015 Rolling Stone profile of Trump, early on in his presidential campaign, he was quoted as gushing about the capabilities of his own Boeing plane.
"I bought this from Paul Allen and gutted it top to bottom. It's bigger than Air Force One, which is a step down from this in every way. Rolls-Royce engines; seats 43. Did you know it was featured on the Discovery Channel as the world's most luxurious jetliner?" he said.