The transfer of the jet from Qatar to the Trump administration sparked a political firestorm in the spring among Democrats and several influential Republicans.

The free Air Force One from Qatar, which Trump has described as a gift, has raised eyebrows after a $934 million transfer of funds was made to an unnamed classified project from the Pentagon, with officials in the Air Force saying that millions of dollars were needed to pay for renovating the aircraft.

The aircraft - valued at $400m - is being donated by Qatar as an "unconditional gift", with any retrofitting costs being borne by the US government.