Victoria has also reintroduced the 72-hour self-isolation requirement for all international arrivals.
All arrivals must have an international passenger travel permit and take a PCR test within 24 hours of arriving in the state.
They must take another test between the fifth or seventh day after arrival.
Unvaccinated travellers must spend 14 days in hotel quarantine.
Government sources said the Victorian Government was considering extending quarantine and reintroducing mask mandates in some settings.
New health orders could be announced as early as Monday, the sources said, and were likely to be also rolled out by state and territory leaders across the country.
Doubt has been raised whether Queensland will push ahead with its plans to reopen its state borders when 80 per cent of its residents have been fully-vaccinated.
The Sunshine State was expected to hit the target between December 6 and 12 – just weeks before Christmas.
Queensland deputy chief health officer Peter Aitken said he could not guarantee the borders would be reopened without quarantine.
Travellers could be forced to isolate if they visit hotspots in NSW and Victoria.
Deputy premier Steven Miles reassured that ‘nothing has changed at this moment’.
‘So nothing has changed at this stage, but people should be assured that we will continue to take a cautious, well-prepared approach,’ he told reporters on Monday.
‘Our officials are amongst the best in the world. ‘They will monitor the situation very, very closely and they’ll provide advice to us.’
Currently, Queensland plans to scrap quarantine for fully vaccinated domestic travellers once 80 per cent of eligible state residents are fully vaccinated.
It then plans to scrap quarantine for vaccinated international travellers once 90 per cent of Queenslanders are vaccinated.
International arrivals are currently required to go into hotel quarantine while returned travellers from states with open borders must go into home quarantine.
Premier Mark McGowan on Saturday evening shut his state’s borders to South Australia in a draconian effort to lock out the mutant new strain, as it allows in visitors from NSW and Victoria.
The ruling means only vaccinated South Australians can enter WA, where they must immediately go into quarantine for 14 days.
‘The new variant emerged in southern Africa and is now understood to have been detected in Europe, Asia and the Middle East,’ Mr McGowan said.
‘With little known about the variant, it is important we act with an abundance of caution in dealing with potential spread into WA from overseas travellers arriving in other states.’
WA Health Minister Roger Cook was worried that overseas travellers could enter South Australia without quarantine if they came from Victoria, NSW or Canberra.
‘South Australia’s relaxed border policy has seen increased infections from other States, and while they have not yet had community transmission, there is an increased number of exposure sites,’ Mr Cook said.
Travellers from NSW are not permitted to enter WA without approval.
If approved to enter WA, visitors from NSW must immediately self-quarantine in a ‘suitable premises’ for 14 days.
South Australia also tightened its border rules following the emergence of the Omicron variant.
All international travellers and people arriving in SA from high-risk locations in Australia will once again be required to quarantine for 14 days.
Travellers from low-risk or moderate Local Government Areas will be required to get tested for Covid-19 three days before going to the state.
It came less than a week after the state flung open its state borders last Tuesday for the first time in months.
More than 30,000 people have already applied to enter the state with travellers arriving from NSW, Victoria and the ACT.
The state is only accepting fully-vaccinated arrivals while the unvaccinated will need to apply for an exemption, with those applications to be considered on a case-by-case basis.
All vaccinated international travellers who have arrived in the state in the last couple of days must quarantine until November 30.
Unvaccinated arrivals must undergo hotel quarantine for 14 days.
The Northern Territory is only accepting fully-vaccinated travellers, state residents or people who have a medical exemption into the state.
International arrivals are still required to undergo 14 days of hotel quarantine.
Domestic travellers or international arrivals from a red zone can may apply to undergo seven days of home quarantine.
All travellers must complete a Border Entry form before their arrival.
Travellers from low-risk areas in Australia are not required to quarantine.
Arrivals from moderate-risk areas must quarantine at home for 14 days, while those from high-risk areas are not allowed into the state unless they are an essential worker.
International arrivals must be fully-vaccinated and will be required to quarantine for 14 days.