US President Donald Trump unveiled on Friday a replacement Air Force One aircraft gifted by Qatar, which he dubbed a “flying White House”.

“This is considered the world’s most luxurious plane,” Trump said at a speech inside the plane’s hangar, praising the gulf emirate for being “so nice and providing” it.

Qatar’s gift of the aircraft — valued in the hundreds of millions of dollars — has raised ethical, constitutional and security concerns.

Trump has previously said it would be “stupid” to reject the gift, while also stoking further concern by saying the plane would eventually be donated to his presidential library.

At the unveiling on Friday at Joint Base Andrews, just outside Washington, Trump praised the workmanship that went into modifying the jet, saying “with the extraordinary devotion of many of you here today, this plane was transformed into a flying White House at a level of luxury that nobody’s ever seen before”.

“When you see it, you won’t believe it, actually, the quality of woods, the quality of the materials, the quality of the engines,” he added. “And I want to thank the emir of Qatar.”

A pool journalist allowed to tour the inside of the plane reported that it features leather seats, plush carpets, wooden panelling and walls colored tan and light brown with shades of gold.

A framed print of a duck swimming in the Reflecting Pool — a Washington landmark that Trump has sought to beautify with mixed results — is among patriotic-themed pictures to adorn the walls.

Repeatedly praising the size of the aircraft and its engines, Trump said, “it flies further and faster than any Air Force One”.

Trump said the new aircraft would likely participate in a flyover as part of 250th US Independence Day celebrations on July 4.

The US president has fixated on replacing the aircraft, which have been in service since the 1990s, since his first term.

On Thursday, White House officials bade farewell to one of the two heavily modified Boeing 747s that have transported US presidents for decades, which fueled speculation that the new jet would be unveiled imminently.

While the now-replaced aircraft sported a blue and white exterior, the new aircraft has a navy blue underbelly, red stripe and white upper body.

Whenever a US president is on the jet, it officially takes the call sign Air Force One.

The US government has contracted Boeing to deliver two new 747-8 aircraft to serve as part of the presidential fleet, but the program has been plagued by delays and cost-overruns.