Updated

Federal prosecutors say a drunken passenger assaulted a flight attendant while flying from Japan to Honolulu.

Kenji Okamoto pleaded guilty Friday to interfering with a flight attendant's duties by assaulting and intimidating him.

According to a criminal complaint, Okamoto was flying first-class from Osaka for his honeymoon last month when flight attendants noticed he was drunk before takeoff and continued drinking alcohol during the flight.

The court documents say Okamoto got upset when one of the flight attendants wouldn't take his tray away. The flight attendant told him his hands were full. Okamoto allegedly punched a flight attendant who intervened in an attempt to diffuse the situation.

The Delta Air Lines flight crew told authorities that Okamoto later apologized while crying.

He faces a maximum 20-year prison sentence.