MIAMI (Reuters) - An airline passenger who allegedly urinated on a row of seats and threatened to bring down his Argentina-bound flight in a fireball was indicted in Miami on charges of interfering with a flight crew and making threats on a commercial aircraft, prosecutors say.

The United Airlines flight from New York to Buenos Aires was diverted to Miami International Airport on Christmas Day because of the man's behavior, said U.S. Attorney Guy Lewis.

The suspect, Rodrigo Deambrosio, faces up to 20 years in prison if convicted on the charges, Lewis said Friday.

He said Deambrosio, a waiter from New York, became unruly two hours after the flight left New York's Kennedy airport, cursing at the crew and refusing to return to his seat.

Told the plane would land unless he behaved, Deambrosio urinated in the row of seats where he had been sitting, Lewis said in a news release.

Flight attendants stood guard over him as the plane turned toward Miami. Deambrosio allegedly told them he could not wait to be thrown off the plane because he had placed something aboard that would prevent it from ever reaching Buenos Aires, Lewis said.

"Deambrosio stated that he had ways of putting things on planes because he is a waiter in New York and he knows how the catering service works for the airlines," the prosecutor said.

"Deambrosio then stated that everyone on the plane was going to die in a fireball. ... After landing at Miami International Airport, Deambrosio stated again that the passengers and flight crew would die."

He was arrested after the plane landed safely in Miami and told the crew that he had consumed alcohol, prescription sleeping tablets and cocaine before boarding, Lewis said.