But to convince a court that the self-styled Cuban militant committed perjury, prosecutors must prove he participated in the attacks. In court documents, prosecutors have already signaled that they will call two Cuban police officials and present forensic evidence about the 1997 explosions, in which one Italian tourist died. They will also submit tapes and transcripts of interviews of Mr. Posada by a reporter for The New York Times in 1998. In the interviews, he boasted that he had organized the wave of seven bombings at hotels, restaurants and nightclubs.

The trial will be closely watched by officials in Cuba and Venezuela and may be a turning point in relations between the United States and the leftist governments in those countries.

Image Mr. Posada, a Cuban exile who worked for the C.I.A. and sought to push Fidel Castro from power in Cuba, is accused of lying to an immigration judge about his role in the bombings at Havana tourist spots in 1997. Credit... Jose Goitia/Associated Press

For years, Cuba and Venezuela had been clamoring for Mr. Posada to be extradited to their countries to stand trial. In Venezuela, he remains a prime suspect in the bombing of a Cubana Airlines flight that crashed off the coast of Barbados on Oct. 6, 1976, killing all 73 people aboard. Though he was never convicted, he was imprisoned for nine years in Caracas on charges of conspiring with the bombers. He escaped by bribing a warden and walking out of prison disguised as a priest.

Cuban officials regard him as a terrorist mastermind and have repeatedly accused the United States of harboring “the bin Laden of this hemisphere.” Not only did he say in interviews with The Times that he had orchestrated the Havana bombings in 1997, but he also was convicted in 2000 in Panama of taking part in a plot to assassinate Mr. Castro at a summit meeting. He served four years in prison there before being pardoned by President Mireya Moscoso in her last week in office.

Mr. Posada has long been entwined with American intelligence services, going back to the failed Bay of Pigs invasion in 1961. He worked directly for the agency until 1967, spying on Cuban exile groups in Miami and running paramilitary training camps, according to declassified documents. He was also a “paid asset” of the agency in Venezuela from 1968 to 1976, according to declassified documents and an unclassified summary of his career in the court record.

“The C.I.A. taught us everything — everything,” he told The Times in 1998. “They taught us explosives, how to kill, bomb trained us in acts of sabotage.”