President-elect Donald Trump took aim — again — at the U.S. military’s most expensive weapons program, faulting defense giant Lockheed Martin for heavy costs and signaled he is looking for an alternative to the F-35 stealth fighter program.

In a post on Twitter Thursday afternoon, Trump singled out the sophisticated fighter jet for “tremendous cost and cost overruns,” and said he “asked Boeing to price-out a comparable F-18 Super Hornet!”

Variants of the F/A-18 have been mainstays of the Navy and Marine Corps fleets for more than two decades. The aircraft are aging but capable fighters that the F-35 is designed, at least in part, to replace. The Navy has been buying more of the aircraft carrier capable planes in recent years because of F-35 production delays.

Trump's message to his millions of followers came a day after separate meetings with the CEOs of Lockheed and rival Boeing. Trump has lashed out at both Lockheed's F-35 program and at the potential high cost of the next presidential jet, known as Air Force One when the head of state is aboard, which would likely be a pair of newer 747s built by Boeing.

Both aircraft programs have Georgia ties. Lockheed's sprawling plant in Cobb County makes center wing assemblies for the F-35 program. More than 5,000 people are employed at the factory at Dobbins Air Reserve Base.

This fall, Pond & Co., a Georgia-based design firm, announced it and a partner had won a contract to design a new hangar facility in Maryland for the future executive aircraft.

The $379 billion F-35 program, known as the Joint Strike Fighter, comes in variants for the Air Force, Navy and Marine Corps. Lockheed plans to sell the next-generation fighter to a number of U.S. allies, including Japan, Israel, South Korea and the U.K.

The F-35 uses stealth technology to avoid being detected by radar. The Navy’s version, for example, is designed to take off and land on an aircraft carrier.

Current plans call for the United States to buy nearly 2,500 F-35s. Close to $13 billion will be needed annually between 2016 and 2038 to hit that procurement number, according to the Government Accountability Office.

The F-35 was plagued by cost overruns early on, but the cost of per jet is expected to decline rapidly as the planes enter service and more are purchased by allied nations.

Earlier this month, Trump complained on Twitter that costs for the future Air Force One were "out of control, more than $4 billion. Cancel order!"

The Wall Street Journal reported earlier this month the Air Force uses modified 747-200 jets that have been in service since the administration of President George H.W. Bush, and which reach the planned end of their 30-year service life next year. The Journal reported Boeing has a contract to begin development work to replace the planes with modified 747-800s.

Separately, the Air Force has about $1.65 billion — less than half the $4 billion figure Trump tweeted — earmarked across several budget years for the jets, which would be put into service in 2023 or 2024. But that might not be the full cost of the program, and NBC News reported Trump is likely correct about the overall price of the program including research, development and other costs.

Following his meeting with Trump on Wednesday, Boeing CEO Dennis Muilenburg told the media his company would work to rein in the cost of the Air Force One program.

"We work on Air Force One because it's important to our country," he said, according to USA Today, "and we're going to make sure that he gets the best capability and that it's done affordably."

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The Associated Press contributed to this report.