WASHINGTON — The top speed of Donald Trump’s business jet? Currently 0 mph.

The billionaire GOP candidate’s 750 Citation X — in use lately to travel to campaign events — is grounded because its registration has expired.

Federal Aviation Administration inspectors have contacted the jet’s chief pilot about the plane’s registration, which expired in January, the FAA said in a statement Wednesday.

The plane’s owner “is currently working with the FAA’s aircraft registry and will re-register the aircraft before further flight,” the statement said.

The plane is registered to a limited liability company whose sole member is Donald Trump. The plane’s identification number, N725DT, also includes Trump’s initials.

The Republican presidential candidate has been using the jet to travel to campaign events. It seats up to eight people. Trump also owns a Boeing 757 airliner and three helicopters.

Trump’s campaign declined to comment.