Washington - US Defence Secretary Robert Gates on Monday recommended two men to head the Air Force after last week sacking the military branch's leadership after two serious breaches of nuclear security in less than a year.

He asked President George W Bush to nominate Michael Donley to become the civilian secretary of the Air Force and General Norton Schwartz to become its chief of staff, the top military position.

Air Force Secretary Michael Wynne and Chief of Staff Michael Moseley were both asked to leave after an internal investigation revealed that a "pattern of poor performance" and failure of leadership had led to two mishaps, Gates said Thursday.

The US in March said it mistakenly shipped fuses for detonating nuclear warheads to Taiwan. In August, a B-52 bomber was accidentally loaded with six nuclear bombs in a 1,200-kilometre flight between two bases within the United States.

Gates blamed "systemic weaknesses," a failure of oversight and "lack of a critical self-assessment" at the Air Force for the two errors, both of which could have been prevented.

Donley currently oversees the Pentagon's operations as the Defence Department's director of administration and management, and Schwartz leads the US Transportation Command.

The men must first be nominated by Bush and confirmed by the US Senate. (dpa)