Pedro Fuentes, ex-political prisoner, sat in the Havana airport terminal Wednesday night waiting for the flight that would take him out of Cuba for the first time in 17 years.

Every few minutes, a group of his friends standing on the sidewalk outside banged on the terminal window. Each time, Fuentes walked over and, separated from them by a wall of glass, joined them in a silent conversation using the broad gestures of the sign language they had once used to communicate across prison yards.

"I don't like to see them like that," he said of his bon voyage committee outside. "It's like they're still in jail."

Fuentes, 39, was traveling that night as the former prisoners' emissary to Venezuela, where the government has offered to admit at least 1,500 of approximately 12,000 former political prisoners President Fidel Castro recently said are now eligible to leave the country.

Most of the ex-prisoners and their families, including himself, Fuentes said, would rather go to the United States. But the United States, he said, does not seem to want them.

U.S. consular officials here say that is not true. Nearly all the ex-prisoners, most of whom have relatives or other sponsors in the United States, are eligible for U.S. immigration.

But it will take time. The Justice Department recently announced a special refugee program to speed the immigration of up to 3,500 current prisoners Castro has also authorized to leave the country. But the ex-prisoners-those who had already served their time for "counterrevolutionary activities" and now live and work in varyin degrees of freedom here-are to be treated just like any other potential immigrant.

That means a three- to five-week wait for a routine security name check, and more paperwork once processing of an application is begun. Considering the hundreds of eligible Cuban applicants who have shown up daily at the U.S. Interests Section here since Castro's program was announced last September, it could take months, or maybe even years, to process all of them.

Many of the ex-prisoners fear that the exit door, temporarily opened for others in the past 20 years, only to be slammed shut again, will close before their turns come up.

The plight of the former political prisoners has caused confusion, resentment and political gamesmanship both here and in the United States.

In a press conference last week, Castro said the United States has a "moral obligation" to help both the prisoners and ex-prisoners. They became counterrevolutionaries, with U.S. support, he said.

Present at the press conference was a group of 140 visiting Cuban exiles, primarily from the United States, with whom Castro negotiated the release program. They, too feel the United States is obligated to immdiately take every Cuban Castro is willing to let go-particularly those who have spent time in his jails, both recently and in the past, for trying to overthrow his government.

Opposite this unlikely coalition is the United States, apparently taken by surprise when Castro originally announced the release program. Unwilling to snap to attention when Castro gave the word, the Justice Department first balked at immediate acceptance of as many as 50,000 Cubans, including prisoners, ex-prisoners and their families, without thorough security screening.

That attitude opened the U.S. government-which admitted as many as 1,000 Cubans a week in the early 1960s during a massive flight from the then new communist state-to a criticism on human rights grounds.

By the time the final release agreement between Castro and the exiles was signed here Dec. 8, the United States had agreed to speed the admission process-but only for those Cubans still in prison or freed within the last six months.

The ex-prisoners seem astounded that the United States has refused to authorize a special Program to admit them immediately en masse. For many of them, although they may have been out of prison for a number of years, time stopped in the early 1960s, when the U.S. government actively supported their efforts against Castro, and opened its arms to all who opposed him.

Intellectually, they appear to realize that their time to leave eventually will come. Emotionally, the long years of waiting, blaming the Cuban government as the sole impediment to their joining their families, have made it difficult for them to wait any more now that that impendiment has been removed.

Their stories, which they tell to any visiting exile or reporter who will listen, in efoorts to get their names to the top of the visa list, are strikingly similar.

For the first five years of the Castro government, Gloria Alvarez Medina, a pretty, dark-haired woman now 50, operated a Havana "safe house" used for smuggling Cuban children out of the country. It was not until 1965, she said, that the government "discovered everything" and arrested her. Accused of being a CIA collaborator, she was sentence to nine years by a military tribunal.

Her husband, and officer in the previous government's army, had long since fled Cuba and shortly after her sentencing, in one of the brief openings Castro allowed, her parents and 12-year-old daughter left for Miami. She has not seen them since.

When she was paroled in 1971, Alvarez said, "everyone was afraid" to take her in.

"No one would give me a house to live in, and I moved from one to the other." When she remarried, "my husband's sister threw him out."

Today, Alvarez and her husband, who also has a daughter in the United States, live in someone's extra room. Conditions are not as bad as they once were for ex-prisoners in Cuba, she said.

"We have rights now," she said, and the government "considers us human beings."

But, she said, "they know our minds are never going to change" and as opponents, the government wants them out.

"For the past seven years," she said, "I have asked permission to leave the country. My father is now 80, my mother 78. My daughter is married."

Now, with a ticket that her daughter has sent, the waiting is nearly unbearable.

Jose Enrigue Bringuier, 59, said he was head of the cattlemen's association in pre-revolutionary Cuba and spent 4 1/2 years in prison in the early 1960s because he opposed Castro's land reform program.

After his release, he married, and he and his wife Albertina, 57, were arrested in 1964 for "espionage and CIA collaboration." They were both paroled 18 months ago.

Today, the couple lives with Jose's widowed stepmother. Although Bringuier, an attorney, has been reissued an employment card by the government, he said none of the state-run law firms will take him on.

His wife, Albertina, has three children in the United States.

"I haven't seen them in 17 years," she said. "I don't even know what they look like."