The former secretaries -- Henry Kissinger, James Baker, Warren Christopher, Madeleine Albright and Colin Powell -- were part of a roundtable discussion at the University of Georgia, offering "bipartisan advice" to the next administration, The Journal-Constitution in Atlanta reported Friday.
"Our image abroad has dropped significantly," said Powell, secretary of state when the prison opened. "Perhaps this administration has spoken a little too harshly in a unilateral way."
The prison's closure would signal "we are now going to go back to our traditional, respected way of dealing with people who have potentially committed crimes," Powell said.
Kissinger said that not all of the criticism is because of U.S. actions.
"Some of it is also due to structural changes going on in other parts of the world," he said.
The five also agreed the United States should talk to its enemies, including Iran.
"We have to understand what diplomacy is really about," Albright said. "It's talking to your enemy."