Donald Trump’s online, bragging about a “flying palace” — a luxury plane gifted from Qatar’s royal family slated to serve as one of the presidential Air Force One fleet of jumbo jets … but it’s causing a stir, since accepting foreign gifts like that is legally questionable.

The $400 million Boeing 747-8 — AKA the world’s biggest plane — could be Trump’s new Air Force One for the rest of his term … and it’s being called one of the priciest gifts ever from a foreign power to the U.S.

Trump posted on Truth Social: “So the fact that the Defense Department is getting a GIFT, FREE OF CHARGE, of a 747 aircraft to replace the 40 year old Air Force One, temporarily, in a very public and transparent transaction, so bothers the Crooked Democrats that they insist we pay, TOP DOLLAR, for the plane. Anybody can do that! The Dems are World Class Losers!!!”

The Trump admin’s already facing heat, as this plane would violate a constitutional ban on gifts from foreign governments. But, the White House and Justice Department are arguing it’s not a gift to an individual, so it’s all good — it’s set to be transferred to the U.S. Defense Department, and would then transfer to the ownership of Trump’s presidential library foundation when his current term expires.

There are currently two Air Force One Boeing planes in use — though one is in the shop for routine maintenance. The planes are custom-designed for security and to allow the president to communicate across the globe at all times, and can be refueled mid-flight.

Trump is scheduled to fly to the region this week, with a stop in Qatar, where Donald’s son Eric Trump recently completed a golf club deal in the country worth $5.5 billion, ABC News reports.