Government extends defence chief term

Additionally, the government has requested the term of the chief of joint operations, Lieutenant General Greg Bilton, also be extended for two years.

Acting Prime Minister Richard Marles made the announcement on Tuesday and said the government recognised the burden placed on those in the roles.

He said significant defence capability challenges such as submarine procurement meant continuity of ADF leadership was important.

"We are mindful of the size of the ask that we are making on these three individuals; these are really big jobs," Mr Marles told reporters in Canberra.

"Continuity will serve us well ... we cannot afford any more delay in terms of delivering Australia's new submarine capability."

A former army chief, General Campbell was first appointed head of defence in 2018.

Mr Marles said while not unprecedented, it was unusual for an Australian chief of defence force to serve what will be a six-year term. 

"We will work together to do our very best to see the defence of this nation and the development of the force and its people," General Campbell said on Tuesday. 

A new team of navy, army and air force heads was also announced. 

Vice Admiral Mark Hammond has been selected as navy chief, Lieutenant General Simon Stuart will be head of the army and Air Marshal Robert Chipman will lead the air force. 

Mr Marles thanked outgoing chiefs Vice Admiral Michael Noonan (navy), Lieutenant General Rick Burr (army) and Air Marshal Mel Hupfeld (air force) for their service.

Opposition Leader and former defence minister Peter Dutton hit back at comments from Mr Marles about defence capability gaps caused by the previous government.

"It just defies logic because when Labor were in government they reduced spending in defence to the lowest level since 1938," he said.

"It's an absurd comment for him to make, and frankly, beneath him on when we really should be celebrating the extension of General Campbell and the other appointments."