The comments came shortly after the prime minister, Laisenia Qarese, said he would offer a range of concessions to the military in the hope of averting a coup.
Commodore Frank Bainimarama was speaking a day after talks in New Zealand with Qarese and said the government had until Friday afternoon to answer his demands.
If not, he said, "then we will take as given that we have been endorsed to do the cleaning up campaign in Fiji."
"We hope this is going to be a peaceful transition, because we don't expect any confrontation nor do we expect any opposition,'' he said.
Last Mod: 20 Eylül 2018, 18:16
On Thursday morning Fijian troops returned to barracks after overnight exercises in and around the capital, Suva.
Bainimarama has repeatedly threatened to "clean up" the Fijian government if it does not give in to his demands.
|Bainimarama says the PM has until |
Friday afternoon to yield to his demands
Despite military assurances that the exercises were aimed at deterring foreign intervention in the ongoing crisis, the deployment and call-up of reserves has added to speculation that a coup is imminent.
The Australian government, fearing the worst, has begun evacuating the families of its embassy staff from Suva.
Australia, Britain and New Zealand have also issued travel advisories to their nationals against visiting Fiji.
Meanwhile local residents, fearing a fourth coup in two decades, have begun stocking up on food and cash.
Outlining his proposed concessions to military demands, Qarase urged a quick response to his offer hinting the government would welcome a recommendation from prosecutors not to press sedition charges against Bainimarama for comments against the government.
Bainimarama has repeatedly threatened to remove Qarase's government unless several proposed laws were dropped including one that would grant amnesty to those involved in a coup six years ago.
Foreign ministers of the Pacific Island Forum, a regional pact, are scheduled to meet on Friday in Sydney to discuss the crisis, prompting Bainimarama to warn them to back off.