WASHINGTON -- Former Vice President Dick Cheney said Monday he supports gays being able to marry but believes states, not the federal government, should make the decision.

"I think, you know, freedom means freedom for everyone," Cheney said in a speech at the National Press Club. "I think people ought to be free to enter into any kind of union they wish, any kind of arrangement they wish."

Cheney, who has a gay daughter, said marriage has always been a state issue.

"And I think that's the way it ought to be handled today, that is, on a state-by-state basis. Different states will make different decisions. But I don't have any problem with that. I think people ought to get a shot at that," he said.

Cheney spent most of his speech, and during the questions and answers that followed, defending the Bush administration's wartime policies.

He said that the jail at Guantanamo Bay Naval Base in Cuba was necessary because its prisoners are too dangerous to be held elsewhere.

"If you don't have a place where you can hold these people, the only other option is to kill them, and we don't operate that way," he said.

The 240 prisoners left at Guantanamo, he said, are "the worst of the worst" -- including alleged Sept. 11 mastermind Khalid Sheik Muhammed-- who would gladly become suicide bombers to kill more Americans.

Cheney said if the jail had not existed, captured terrorists would have had to have been brought to the United States where they would have legal rights denied to them at Guantanamo. He did not address why the prisoners could not have been held at U.S. military jails in war zones like Afghanistan and Iraq, where some newly captured prisoners are going now.

Cheney reiterated his challenge to President Barack Obama to release several pages of secret memos that Cheney says will prove that harsh interrogations were effective. His initial request to release the memos was turned down last month because the documents are the subject of a Freedom of Information Act lawsuit and may be released by a court.

Cheney noted that Obama in April superseded another FOIA lawsuit to release the memos describing the CIA's harsh interrogation program, which he called "giving away the store."

Cheney also defended the Bush administration's decision to invade Iraq in 2003, despite faulty intelligence about its nuclear weapons program and links to the 9/11 attacks. He asserted that Saddam Hussein could have helped terrorists acquire nuclear weapons. The U.S. government could find no evidence of an active Iraq nuclear weapons program after the invasion.

More than 4,300 U.S. service members have died in Iraq, with more than 30,000 wounded. Tens of thousands of Iraqis have been killed in the 6-year-old war that has cost the United States about $675 billion so far, according to the National Priorities Project.

Cheney is writing a memoir about his years in government, which he said will highlight the successes of the policies set in place after the terrorist attacks of Sept. 11, 2001.