"I want to send a message to the FARC," Gonsalves said.
"FARC, you guys are terrorists. You deny that you are, you say with words that you're not terrorists, but your words don't have any value. Don't tell us that you're not terrorists, show us that you're not terrorists."
Gonsalves made the remarks at a ceremony welcoming him and two other U.S. military contractors - Thomas Howes and Keith Stansell - home after their time in captivity. The military said the hostages would take no questions from reporters.
"Almost 5½ years ago we fell off the edge of the earth. ... We are doing well but we cannot forget those we left behind in captivity," Howes said.
Family members, some wiping tears, also expressed their gratitude for their loved ones' rescue.
Gonsalves, who was much thinner than he seemed in a pre-captivity picture on display at the ceremony, said he believed the guerrilla group was punishing others because the three men and former Colombian presidential candidate Ingrid Betancourt were rescued.
He said a hostage with a chain around his neck would be forced to march while carrying a heavy backpack and a guerrilla armed with an automatic weapon held the other end of the chain "like a dog."
"They say that they want equality, they say that they just want to make Colombia a better place," Gonsalves said. "But that's all a lie."
Betancourt on Monday advised President Alvaro Uribe of Colombia to tone down the "radical, extremist language of hate" toward her former captors.
The men had been held by the FARC since their drug-surveillance plane went down in the jungle in February 2003. They were rescued when Colombian spies tricked their rebel captors into handing them over. Eleven members of the Colombian security forces also were released.
The men, employees of a Northrop Grumman Corp. subsidiary, arrived in the U.S. late Wednesday and were taken by helicopter to Fort Sam Houston's Brooke Army Medical Center, where they have been treated.
Col. Jackie Hayes, chief of pulmonary and critical care at the medical center, said the men "in general fared very well" and that examinations have "not revealed any significant medical problems."
"At this time we believe that they are all very healthy," Hayes said.
The men, who spoke in an auditorium adorned with large yellow ribbons and an American flag, thanked their families, the Colombian military, the U.S. government and Northrop Grumman.
"They are the reason I'm alive and standing right here with all of you today," Stansell said of his family.
Stansell provided one of the lighter moments when, from the podium, he asked Florida Gov. Charlie Crist for a new driver's license so he could get home.
The men waved as they got a lengthy standing ovation from uniformed military in the audience.
"It's a pleasure to be in the USA," Howes said, giving a thumbs-up.
