A 67-year-old man on Thursday admitted hijacking a plane four decades ago and forcing it to land in Cuba, telling a judge how he threatened to cut a flight attendant's throat to get access to the cockpit, where another man held a gun to the back of the co-pilot.

Luis Armando Pena Soltren revealed the details of the hijacking, highlighting the violence and frightening nature of the encounter.

Pena Soltren, a US resident, returned to the United States in October, something his lawyer said he had been seeking to do for decades because he was remorseful. He entered his plea to charges of conspiracy to commit air piracy, interfering with a flight crew and kidnapping in federal court in Manhattan. Sentencing was set for June 29.