Australia's hotel quarantine won't be run by the federal government, with the prime minister again rejecting the idea in the wake of renewed concerns about coronavirus spreading out of the system.
"We're not going to be running it," Scott Morrison told 3AW radio on Friday.
"Hotel quarantine is never 100 per cent fail safe. To suggest it ever will be is just not realistic."
International arrivals have to complete 14 days in hotel quarantine in order to protect the community from coronavirus, with breaches of the system Australia's greatest risk of the disease spreading.
The entire state of Victoria will begin a strict five-day lockdown from Saturday in a bid to stop an outbreak of the highly infectious UK variant growing.
The cluster is linked to the Holiday Inn at Melbourne Airport and consists of 13 cases as of Friday, with a total of 19 infections in the state.
Victorian Premier Dan Andrews flagged changes to his state's hotel quarantine system, while the government announced a pause on international flights during the short lockdown.
Victoria's weekly international arrival limit was due to increase to 1310 on Monday, but Mr Andrews says he'd rather that number be in the hundreds.
"The game has changed," he told reporters in Melbourne.
"This thing is not the 2020 virus, it is very different. It is much faster. It spreads much more easily."
Victoria's lockdown has prompted other jurisdictions to tighten restrictions on travel to and from the state.
Hotel quarantine workers have also caught the virus in Perth, Brisbane, Adelaide and Sydney, sparking brief lockdowns in those cities.
Mr Morrison said states were sharing information about their quarantine systems to help it improve.
"That doesn't mean it can't fail, of course it can fail, any system can fail."
Deputy Opposition Leader Richard Marles insists a Labor government would take the reins of the hotel quarantine system.
"Quarantine is right front and centre of what the federal government is about," he told Nine.
Western Australia and Queensland are pushing for regional quarantine hubs while Victoria wants the federal government to look at building new facilities.
Queensland Premier Annastacia Palaszcuk has proposed moving quarantine from city hotels to accommodation near Gladstone in the central part of the state.
But Home Affairs Minister Peter Dutton - who is responsible for the nation's international borders - says it would take up to 18 months for a facility to be built.
"We've got hotels that are sitting empty around the country, that have catering, that have security, that have ensuite arrangements, it suits the requirements of the health authorities," he told Nine's Today show.
About 220,000 people have gone through Australia's hotel quarantine system.