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.
The missiles came down in areas near a new U.S. consulate building, according to Kurdish officials. U.S. officials said no Americans were hurt and nor were U.S. facilities hit. Kurdish authorities said only one civilian was hurt and no one killed.