Cheney said the prison at Guantanamo Bay could be responsibly shut down only when the war on terror has ended. Asked when that might be, he added, "Well, nobody knows. Nobody can specify that."
"A lot of people, including the president, expressed the view that they'd like to close Guantanamo," he said. "I think everybody can say we wished there were no necessity for Guantanamo, but you have to be able to answer these other questions before you can do that responsibly."
Cheney warned that prisoners released from Guantanamo could prove dangerous to the United States, adding that the problem of what to do with released prisoners had not yet been solved.
"If you release people that shouldn't have been released -- and that's happened in some cases already -- you end up with them back on the battlefield," he said.
Cheney said the Guantanamo detainees have been "well treated."
"I don't know any other nation in the world that would do what we've done in terms of taking care of people who are avowed enemies, and many of whom still swear up and down that their only objective is to kill more Americans," he said.
Read excerpts from Monday's interview here.
ABC News' Kate Barrett contributed to this report.