Lockheed Martin lost as much as four percent of its total value in the moments after US president-elect Donald Trump tweeted that the cost of the military jet maker's project to build advanced F-35 Lightning II fighters was "out of control."

Panicked investors dumping stock initially shaved off around $3.5 billion (£2.75 billion) from the company's value, though the share price had recovered somewhat by the close of trading on Monday, leaving it nearly 2.5 percent down on the previous day, or a dip of around $2 billion (£1.57 billion).

The F-35 program and cost is out of control. Billions of dollars can and will be saved on military (and other) purchases after January 20th. — Donald J. Trump (@realDonaldTrump) December 12, 2016

Trump claimed "billions of dollars can and will be saved on military purchases" after he is inaugurated as president of the US.

The US government's procurement deal for Lockheed's F-35 joint strike fighter is its most expensive ever—with costs said to be currently hovering around $400 billion (£314.5 billion), $100 billion (£78.7 billion) of which has already been spent, according to the New York Times. The project has been beset by cost overruns and hitches in both software and hardware throughout its 15-year history, and the first F-35 squadron only entered service in August, when fresh upgrades meant that pilots had managed "88 individual aircraft sorties without a software problem."

Last year, a test pilot admitted that the new fighter was at a disadvantage in dogfights with the venerable F-16, a fighter first introduced in 1978, because it climbed and turned slower.

In a markedly meek response to the future US president, Lockheed's F-35 general manager, Jeff Babione, described it as “the most advanced aircraft in history,” claimed that the company understood "the importance of affordability," and said that he believed the price of each aircraft would end up at $85 million (£66.9 million) by 2019 or 2020. Depending on the model, each unit currently costs between $98 and $116 million (£77-£91 million).



We understand it’s not just the acquisition price. Lockheed Martin and its industry partners are also investing in reducing the sustainment costs of the aircraft recognising that much of the cost of owning and operating an aircraft is after it’s delivered. We plan to invest hundreds of millions of dollars in an effort to reduce the cost of sustaining the airplane over its 30-40 year lifespan. We understand the importance of affordability and that’s what the F-35 has been about.

Regular Trump opponent and chair of the US Senate's armed services committee, John McCain, told Reuters he supported cost cutbacks to the project, saying: "He can reduce the buy over time, next year, as we look at it again."

Despite its many issues, the F-35 has broad political support across the US, because Lockheed has subcontracted manufacturing and engineering projects across many states. All of these provide jobs, making it tricky for elected officials to be critical of the project. The UK, Australia, Israel, Japan, and the Netherlands have all placed significant orders for the aircraft, with Britain investing $2.5 billion (£1.97 billion) as the sole "Level One" partner.

Last week, another of Trump's tweets caused a bump in Boeing's stock price. The right-winger and former reality TV star hit out at the company for the cost of replacing the presidential aircraft, Air Force One, shaving 1.5 percent from its value.