NEW YORK (AP) — A man accused of hijacking an airliner four decades ago has pleaded not guilty in a New York City courtroom.

Luis Armando Pena Soltren remained jailed Tuesday after a brief appearance before a federal magistrate judge in Manhattan.

Authorities say the U.S. citizen and his accomplices used weapons they hid in a diaper bag to hijack a Pan Am flight from Kennedy Airport to Cuba in 1968.

Pena Soltren has been in Cuba since. He was arrested Sunday after arriving in New York on a flight from Havana. The FBI and federal prosecutors say the Cuban government authorized Pena Soltren's departure and was aware of his desire to return voluntarily.

Robert Pastor, a professor at American University in Washington, says other American fugitives hiding in Cuba are watching the case.