Mariano Faget, 54, who had secret clearance for 12 years with the Immigration and Naturalization Service, stood silently during the brief hearing. Attorney Diane Ward, who was standing in for Faget's lawyer, spoke for him.
"I know in this case it's a very adamant plea of not guilty," she said outside court. "He is adamant that he is not guilty of these charges. He is adamant that he did not do anything to betray his country."
Assistant U.S. Attorney Richard Gregorie notified the court that the case will involve classified information which will require Faget's attorney, Ed O'Donnell, to be cleared to handle government secrets.
Invoking the Classified Information Protection Act also means government documents will be filed under seal and the public will be barred from hearings or parts of them.
Faget, a Havana native who became a U.S. citizen, was indicted Friday on charges that he relayed U.S. secrets to a Cuban friend and lied about contacts with Cuban government agents and officials over a 14-month period.
Despite pledges of $2 million bond, he has been held without bond since his high-profile arrest Feb. 17.
The case led to the expulsion from the United States of a top Cuban diplomat, Jose Imperatori.
In a jailhouse interview this week, Faget denied spying for the Cuban government and said he "would never do anything to hurt the American dream."
The indictment offers little of substance beyond information released by the FBI when Faget was arrested.
Faget, 54, was regularly consulted about immigration cases involving FBI informants and counterintelligence sources, the indictment said.
He never informed the agency about becoming executive vice president of America-Cuba Inc., a company formed with New York businessman and Cuban citizen Pedro Font to recruit trade with Cuba if the United States lifts its trade embargo.
The indictment indicated that Faget should have submitted an outside employment form reflecting his ties to America-Cuba and to Font, its president.
Faget was introduced to Cuban government officials by Font, met with them at least three times and talked to them by phone without reporting his contacts to the FBI or INS, the indictment said.
He was caught in an FBI sting Feb. 11 when he was shown secret documents and told "very sensitive" information about a Cuban official about to defect. He called Font 12 minutes later, investigators said.
In a second call, Faget promised to keep Font informed while he was traveling in China, the indictment said.
The false-statement counts charge Faget lied about contacts with Cuban government officials and lied on a 1998 INS form saying he had no foreign business connections.
If convicted, Faget could face up to 35 years in pison and $1.25 million in fines.