WASHINGTON: The United States has accepted a luxury Boeing 747 jetliner as a gift from Qatar and the Air Force has been asked to find a way to rapidly upgrade it for use as a new Air Force One to transport President Donald Trump, the Pentagon said on Wednesday.

Secretary of Defense Pete Hegseth accepted the jet for use as Trump's official plane, the Pentagon said.

Pentagon spokesperson Sean Parnell said the Defense Department “will work to ensure proper security measures and functional-mission requirements are considered.”

Legal experts have questioned the scope of laws relating to gifts from foreign governments that aim to thwart corruption and improper influence. Democrats have also sought to block the handover.

“Today marks a dark day in history: the president of the United States of America officially accepted the largest bribe from a foreign government in American history,“ Senate Democratic Leader Chuck Schumer said.

The “unprecedented action is a stain on the office of the presidency and cannot go unanswered,“ he added.

Qatar has dismissed concerns about the aircraft deal. Trump has also shrugged off ethical concerns, saying it would be “stupid” not to accept the 747-8 jet.

When new, the jet had a $400 million list price, but analysts at Cirium said a second-hand 747-8 might fetch a quarter of that.

Retrofitting the 13-year-old plane, which has a luxurious interior, will require significant security upgrades, communications improvements to prevent spies from listening in and the ability to fend off incoming missiles, experts say.

The plane might need fighter jet escorts and could be restricted to flying inside the U.S. unless costly security upgrades were made, aviation experts and industry sources said previously.

Democratic Senators Mazie Hirono and Tammy Duckworth said on Tuesday it could cost more than $1 billion to retrofit the plane and it raised dramatic security risks.

Duckworth said the United States has two fully operational Air Force One jets and has no need to retrofit the Qatari plane.

“Any civilian aircraft will take significant modifications,“ Air Force Secretary Troy Meink said at a Senate hearing on Tuesday. “We will make sure we do what’s necessary to ensure security of the aircraft.”

He said the Air Force had been directed to begin planning to address modifications to the plane.

The Pentagon has not said how much it will cost or how long it will take.

The costs could be significant given the cost for Boeing's current effort to build two new Air Force One planes is over $5 billion. The current Air Force One airplanes entered service in 1990.

The Air Force One program has faced chronic delays over the last decade, with the delivery of two new 747-8s slated for 2027, three years behind the previous schedule.

Boeing in 2018 received a $3.9 billion contract to build the two planes for use as Air Force One, though costs have since risen. Boeing has also posted $2.4 billion in charges from the project.

Trump toured the Qatari Boeing plane in February at a Florida airport. CNN reported this week the Trump administration first approached Qatar to ask about acquiring a Boeing 747 that could be used as Air Force One. Trump has said Qatar reached out and offered the jet as a “gift.”

Reuters reported earlier this month the military has tapped L3 Harris Technologies to overhaul the 747. The Qatari plane is currently in San Antonio, Texas, Senator Dick Durbin said on Wednesday.