Western Australia locks out every Australian state and territory

Western Australia has now locked out travellers from every Australian state and territory due to growing concerns about the spread of the Omicron variant.

It comes as Premier Mark McGowan today deemed the Northern Territory an "extreme risk" zone from 12.01am Thursday, January 13.

"We have moved swiftly on Northern Territory, to reduce the risk of more Omicron cases in self-quarantine," Mr McGowan said.

"We know the Omicron variant is spreading rapidly around much of the country and unfortunately the Northern Territory is now too seeing an accelerating caseload in the community."

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Under the "extreme risk" border restrictions, travel is not permitted into Western Australia except under "the most exceptional circumstances".

"Exemptions for approved travellers will be further restricted to Commonwealth and State officials, Members of Parliament, Diplomats, and specialist or extraordinary circumstances determined by the State Emergency Coordinator or the Chief Health Officer," the Western Australian Government said in a statement.

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It is the latest move by the Western Australian government to block the spread of the Omicron variant into the state.

All other states and territories - Queensland, South Australia, New South Wales, Victoria, Tasmania and the ACT - are already "extreme risk" zones.

Western Australia will open its border to all states and territories on February 5.

From that date, international and domestic arrivals will no longer have to quarantine, provided they have been double vaccinated.

International arrivals will still be required to return a negative PCR test 72 hours prior to travel and then require a second PCR test on day two and six on arrival in Perth.

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Unvaccinated travellers must still quarantine in a hotel facility on arrival.

All domestic arrivals into Western Australia must be double-dose vaccinated.

Western Australia is now working to boost their vaccination rates ahead of the February 5 reopening.

"Our controlled border remains a vital tool to protect Western Australia as we work to push our vaccination rates as high as possible towards February 5, including third doses and vaccinations for five- to 11-year-olds," Mr McGowan said.

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Meanwhile, the state recorded four new local COVID-19 cases yesterday and 11 were interstate or internally acquired.

Health Minister Amber-Jade Sanderson said yesterday one of the four new community cases is a family member of a returned traveller from Tasmania, and was infectious in the community.

At least three Omicron cases have been detected in Western Australia in recent days.