President Donald Trump’s confirmation Sunday that the United States may accept a presidential aircraft gifted from Qatar marked the latest escalation in his clash with Boeing, which is years behind on its government contract to build the new Air Force One.

President Donald Trump defended Qatar gifting the U.S. a jet to use as Air Force One as the new fleet is still under construction.

Any donation to this government is always done in full compliance with the law,” White House press secretary Karoline Leavitt said Monday.

Security experts told BI that the work required to make a plane from Qatar ready to be Air Force One would be like building a new plane.