MIAMI (AP) — A former career U.S. diplomat said in court Thursday that he will plead guilty to charges of serving as a secret agent for communist Cuba going back decades, bringing a lightning fast resolution to a case prosecutors described as one of the most brazen betrayals in the history of the U.S. foreign service.

Manuel Rocha, 73, told a federal judge he would admit to two federal counts of conspiring to act as an agent of a foreign government, charges that carry a maximum penalty of between 5 and 10 years in prison each. In exchange, prosecutors agreed to drop 13 additional counts for crimes including wire fraud and making false statements.

Prosecutors and Rocha’s attorney indicated they have agreed upon a sentence but details were not disclosed in court Thursday. He is due back in court on April 12, when he’s likely to be sentenced.

“I am in agreement,” said Rocha, shackled at the hands and ankles, when asked by U.S. District Court Judge Beth Bloom if he wished to change his plea to guilty.

Rocha was arrested by the FBI at his Miami home in December on allegations that he engaged in “clandestine activity” on Cuba’s behalf since at least 1981 — the year he joined the U.S. foreign service — including by meeting with Cuban intelligence operatives and providing false information to U.S. government officials about his contacts.

Federal authorities have said little about exactly what Rocha did to assist Cuba while working at the State Department for two decades at posts in Argentina, Bolivia, Mexico and the U.S. Interests Section in Havana. He followed that with a lucrative post-government career that included a stint as a special adviser to the commander of the U.S. Southern Command.

Instead, the case relies largely on what prosecutors say were Rocha’s own admissions, made over the past year to an undercover FBI agent posing as a Cuban intelligence operative named “Miguel.”

In those recordings, Rocha praised the late Cuban leader Fidel Castro as “Comandante,” branded the U.S. the “enemy” and bragged about his service for more than 40 years as a Cuban mole in the heart of U.S. foreign policy circles, the complaint says.

“What we have done … it’s enormous … more than a Grand Slam,” he was quoted as saying in one of several secretly recorded conversations.

Rocha’s decision to plead guilty Thursday came just hours after the widow of a prominent Cuban dissident killed in a mysterious car crash filed a wrongful death lawsuit against the former diplomat. The lawsuit accuses Rocha of sharing intelligence that emboldened Cuba’s communist leaders to assassinate a chief opponent.

Joshua Goodman And Jim Mustian, The Associated Press