Assange is wanted by U.S. authorities on 18 counts, including a spying charge, relating to WikiLeaks' release of vast troves of confidential U.S. military records and diplomatic cables which Washington said had put lives in danger.
Bush made the comments in a speech during an event in Dallas on Wednesday, while he was criticizing Russia's political system. He jokingly blamed the mistake on his age as the audience burst into laughter.
