Malcolm Turnbull has characterised Zimbabwe as a brutal dictatorship, amid political tensions over an apparent coup in the African nation.
Zimbabwe's long-time ruler Robert Mugabe is under house arrest in the capital Harare after the army declared it was "targeting criminals" within the president's administration.
Mr Mugabe has presided over an oppressive regime and a replacement was yet to be seen, the prime minister said.
"He's been dictator who has committed horrific crimes over a long period of time," Mr Turnbull told Neil Mitchell on 3AW radio on Friday.
The Department of Foreign Affairs and Trade has upgraded its travel advice warning Australians to reconsider their need to travel to Harare.
"There is a heightened security presence in Harare, including armoured vehicles and increased military activity," the advice says.
"Avoid demonstrations, rallies and large-scale public gatherings as they could turn violent."
