WASHINGTON: Defense Secretary Robert Gates ousted the US Air Force's top military and civilian leaders on Thursday, holding them to account in a historic Pentagon shake-up after nuclear missile warhead fuses were mistakenly shipped to Taiwan.

Gates said at a news conference he had accepted the resignations of Air Force Chief of Staff General Michael Moseley and Air Force Secretary Michael Wynne - a highly unusual double firing.

Gates cited two embarrassing incidents in the past year.