Trump indicated that his return journey from the G7 summit in France this week would be the last time he uses the existing fleet.

The plane is estimated to be worth $400 million but the U.S. government has likely spent substantially more to make it ready for use.

The Qatari government’s involvement led to bipartisan criticism that the gift was inappropriate, raising both security and ethical issues. The project to overhaul the plane, including security upgrades, could cost more than $1 billion, according to aviation experts.

Although it is set to be used by the president for official duties, the White House has said the plane will ultimately be given to Trump’s presidential library foundation when he leaves office.

The Air Force said in a press release on Friday that the plane it ready to commence “initial commissioning flights” that will ensure it is ready to safely transport for the president and enable him to fulfill his duties. The plane, referred to by the Air Force as VC-25B Bridge, is now a “secure, modified executive platform,” the statement said.

The plane will “relieve pressure” on the existing fleet that is currently used to transport the president, according to the Air Force.

The Air Force One designation is given to any plane in which the president travels. There are two other planes, both 747 jumbo jets, that are currently used.