MIAMI -

A man who hijacked an airliner from the U.S. to Cuba almost two decades ago has pleaded not guilty to air piracy charges in a Miami federal courtroom.

William Potts has said he returned from Cuba last week to face U.S. justice but nevertheless entered the not guilty plea Wednesday. A bail hearing was postponed after a 1984 arrest warrant surfaced charging Potts with a New Jersey armed robbery.

The 56-year-old Potts could get between 20 years and life in prison if convicted. He seeks credit for the 13 years he spent in Cuban prison for the hijacking.

The FBI says Potts claimed to have explosives aboard the New York-to-Miami flight in 1984, demanding its diversion to Havana. Potts described himself then as a black militant.