In a brief statement, it said the 57-year-old head of the Australian Defence Force would retire on July 3, after more than 40 years of service in the military.

Cosgrove was appointed as defence force chief in 2002, after having earlier commanded Australian-led international intervention in East Timor in 1999, which made him internationally famous and helped win him the title Australian of the Year in 2001.

In recent weeks Cosgrove has commended relief efforts by members of his force in Indonesia's tsunami-devastated province of Aceh.

The statement followed an interview in The Bulletin magazine in which Cosgrove said he had not changed his original intention of retiring when his term as military chief expired.

Earlier in his career Cosgrove also served in the then South Vietnam.