The Australian foreign minister, Alexander Downers, says Canberra will put a ban on travel to and through Australia on all those who join an unconstitutional government in Fiji.
In a statement, Mr Downer says the ban would apply to Commodore Bainimarama, who triggered last week's coup, and his supporters and their families.
Mr Downer says the Fiji military commander and his supporters should be in no doubt that their coup will bring a prompt and sharp international reaction.
He says Australians have been advised to reconsider their need to travel to Fiji and for those in Suva who are concerned about their safety to consider departing.
The British government has already advised its citizens against all but essential travel to Fiji after a state of emergency was declared in the wake of the coup.
The British advisory expresses concern about reports of a warrior group threatening violence against the military unless the elected government is reinstated by Christmas Day.