Fiji has strengthened its strict conditions for entry for all travellers from red list countries.
The Government says this move is in response to the threat of the Covid-19 variant of Omicron
The World Health Organisation has declared the new coronavirus variant to be "of concern".
The WHO said the variant had a large number of mutations, and early evidence suggested a possible increased risk of reinfection.
It was first reported to the WHO from South Africa on 24 November, and has also been identified in Botswana, Belgium, Hong Kong and Israel.
They are all on Fiji's red list countries. Several countries have now banned travel from southern Africa.
Despite Australia confirming its first cases of the strain on Monday, it is not yet on Fiji's red list.
Two people who arrived in Sydney from southern Africa tested positive on Sunday for Omicron and officials have ordered 14-day quarantine for citizens returning from nine African countries.
From December 1, Fiji will welcome visitors from Australia and the United States.
Fiji's Health Secretary James Fong said they are monitoring the Omicron variant closely as it has been "shown to carry significant mutations that could spell higher rates of transmissibility and virulence.
"We commend South Africa on identifying and publishing the first information on this new variant. So far, field evidence does suggest higher transmissibility.
"However, more study is needed to determine if transmissibility is truly increased if the variant is less responsive to natural and vaccine-induced immunity and if the disease caused by the variant is more severe," said Dr Fong.
He said a risk assessment of Fiji's Red List and Travel Partner Countries was "developed with the knowledge that new variants of the virus were highly likely to be detected."
Dr Fong said they will also analyse factors such as country vaccine coverage and rates of community transmission.
"We will continue to rely on that assessment process moving forward.
"All travellers in the Red List countries must be fully vaccinated with one of Fiji's approved vaccines.
"They must also undergo escalated pre-departure protocols, which include self-isolation for the five days prior to travel under the oversight of the employer or sponsor and test negative on day 5 and within 72 hours prior to departure.
"On arrival to Fiji, the quarantine period for travellers from red list countries will increase to 14 days with a PCR test done on arrival, on day 5 and day 12," Dr Fong said.