Richard Armitage (file photo)

Former U.S. Deputy Secretary of State Richard Armitage has acknowledged he disclosed the identity of CIA agent Valerie Plame in conversations to reporters in 2003.

Armitage says he never intended to reveal Plame's identity and that he did not know she was an undercover intelligence agent at the time. He says he disclosed her identity in an offhand manner at the end of a long conversation with a conservative columnist Robert Novak.

Armitage says he immediately notified his superiors at the State Department and other officials when he realized he was the source of the leak.

The leak became a political scandal when Plame's husband, former ambassador Joseph Wilson, accused the White House of disclosing her identity to punish him for his criticism of the Iraq war.

It also led to a grand jury investigation and the resignation of Vice President Dick Cheney's then top aide, Lewis "Scooter" Libby.