In what may be the most valuable gift ever extended to the United States from a foreign government, the Trump administration is preparing to accept a super luxury Boeing 747-8 jumbo jet from the royal family of Qatar -- a gift that is to be available for use by President Donald Trump as the new Air Force One until shortly before he leaves office, at which time ownership of the plane will be transferred to the Trump presidential library foundation, sources familiar with the proposed arrangement told ABC News.

The gift is expected to be announced next week, when Trump visits Qatar on the first foreign trip of his second term, according to sources familiar with the plans.

Trump toured the plane, which is so opulently configured it is known as "a flying palace," while it was parked at the West Palm Beach International Airport in February.

The highly unusual -- unprecedented -- arrangement is sure to raise questions about whether it is legal for the Trump administration, and ultimately, the Trump presidential library foundation, to accept such a valuable gift from a foreign power.

Anticipating those questions, sources told ABC News that lawyers for the White House counsel's office and the Department of Justice drafted an analysis for Defense Secretary Pete Hegseth concluding that is legal for the Department of Defense to accept the aircraft as a gift and later turn it over to the Trump library, and that it does not violate laws against bribery or the Constitution's prohibition (the emoluments clause) of any U.S. government official accepting gifts "from any King, Prince or foreign State."

Sources told ABC News that Attorney General Pam Bondi and Trump's top White House lawyer David Warrington concluded it would be "legally permissible" for the donation of the aircraft to be conditioned on transferring its ownership to Trump's presidential library before the end of his term, according to sources familiar with their determination.

The sources said Bondi provided a legal memorandum addressed to the White House counsel's office last week after Warrington asked her for advice on the legality of the Pentagon accepting such a donation.

The White House and DOJ didn't immediately respond to request for comment. A spokesperson for the Qatari embassy did not respond to ABC's inquiries.

The plane will initially be transferred to the United States Air Force, which will modify the 13-year-old aircraft to meet the U.S. military specifications required for any aircraft used to transport the president of the United States, multiple sources familiar with the proposed arrangement said.

The plane will then be transferred to the Trump Presidential Library Foundation no later than Jan. 1, 2029, and any costs relating to its transfer will be paid for by the U.S. Air Force, the sources told ABC News.

According to aviation industry experts, the estimated value of the aircraft Trump will inherit is about $400 million, and that's without the additional communications security equipment the Air Force will need to add to properly secure and outfit the plane in order to safely transport the commander in chief.

As the Wall Street Journal first reported, the aviation company L3Harris has already been commissioned to overhaul the plane to meet the requirements of a presidential jet.

Both the White House and DOJ concluded that because the gift is not conditioned on any official act, it does not constitute bribery, the sources said. Bondi's legal analysis also says it does not run afoul of the Constitution's prohibition on foreign gifts because the plane is not being given to an individual, but rather to the United States Air Force and, eventually, to the presidential library foundation, the sources said.

The primary aircraft used in the current Air Force One fleet includes two aging Boeing 747-200 jumbo jets that have been operational since 1990. The Air Force contract with Boeing to replace those aircraft has been riddled with delays and cost overruns.

The original contract was signed in 2018, but as of last year, Boeing anticipated the aircraft would not be ready until 2029, after Trump leaves office.

The president has expressed deep frustration with the delays, tasking Elon Musk to work with Boeing and the Air Force to speed up the process. Those efforts have been modestly successful. Boeing's most recent estimated delivery date is now 2027, but Trump has made it clear he wants a new plane this year.