Australia and New Zealand slapped a travel ban and other sanctions against Fiji's military on Tuesday after the army grabbed power in a coup and dismissed the government.
As the coup unfolded, both countries rejected a request by Fiji's embattled Prime Minister Laisenia Qarase for an armed intervention to avert a takeover, arguing it would only have aggravated the situation.
But afterwards, New Zealand Prime Minister Helen Clark blasted the "supreme arrogance" of Fiji's military commander Voreqe Bainimarama and accused him of ripping up the constitution.
"The military commander has just ripped up Fiji's constitution and chucked it out the window," she told New Zealand's Television One.
"It is supreme arrogance to say other people shouldn't break the law when you have just single-handedly set out to destroy the law."
She described Bainimarama's actions as "simply an extraordinary display of military arrogance."
Wellington suspended its defence ties with Fiji and banned Bainimarama from entering New Zealand, where he has family, except to attend talks to end the crisis.
Australian Foreign Minister Alexander Downer, speaking before Bainimarama announced he had taken over the government, announced similar measures.
If the military seized full control, he told parliament, Canberra would ban the military chief and members of any government from travelling to Australia and would suspend military cooperation.
"Over and above that, we would stop Fiji military personnel from visiting Australia and any personnel and the families of people who participate in any interim government," he added.
"None of those people will be welcome in Australia."
Australian Prime Minister John Howard said the coup was a "tragic setback" for Fiji but that he refused a request from Qarase to intervene by force.
"This morning the prime minister of Fiji rang me and asked for Australian military intervention in response to the coup -- I indicated to him that that would not be possible," he told reporters.
"The possibility of Australian and Fijian troops firing on each other in the streets of Suva is not a prospect that I for a moment thought desirable," he said.
New Zealand's Clark confirmed a similar request from Qarase.
"Our judgment is that this would make the situation worse. It is not a step we are contemplating," she said earlier through a spokesman.
Bainimarama, who has been feuding with Qarase's government for months, said he was suspending certain elements of the constitution, taking on the role of president and appointing an interim premier and government.
He had long warned Qarase to resign or face a takeover if he did not bow to a series of demands including the scrapping of controversial legislation.
The United Nations last week urged Fiji's military to hold back and called for a peaceful resolution to the crisis.
It also warned that Fiji would be withdrawn from UN peacekeeping missions.
Fiji has about 1,000 soldiers involved in peacekeeping in the Middle East, Iraq, East Timor and the Solomon Islands, duties which provide a large income and considerable prestige for the military.