Western Australia is set to lock out people from NSW for at least another two months as Sydney deals with a worsening coronavirus outbreak, while Victorians must now quarantine for 14 days upon arrival.
NSW recorded 97 new local cases on Tuesday, prompting the government to extend a lockdown in Greater Sydney and surrounds for at least another fortnight.
Victoria recorded seven new locally acquired cases, six linked to a group of NSW removalists who attended a Maribyrnong apartment complex while infected.
It has prompted WA to reclassify Victoria as a "low risk" jurisdiction under its controlled border regime.
Effective immediately, travellers who have been in Victoria must self-quarantine for 14 days upon arrival at a suitable premise.
They must also present for a COVID-19 test within 48 hours and again on day 11.
"We have to assume that this is the more contagious Delta variant which requires our immediate action," WA Police chief Chris Dawson told reporters on Wednesday.
"The list of exposures sites in Victoria is growing and so is our concern and the risk to Western Australians."
Mr Dawson acknowledged some passengers aboard flights from Melbourne would be caught unaware by the sudden change.
Thursday night's AFL game between Geelong and Fremantle at Optus Stadium is set to go ahead with no crowd restrictions, with the Cats to be placed under strict isolation protocols upon landing in Perth on Wednesday.
WA this week further tightened exemptions for travellers from NSW, including those granted on compassionate grounds.
"WA residents wanting to enter from NSW are not guaranteed right of entry, and need to demonstrate extenuating circumstances to be granted approval to enter WA," the latest travel advice said.
"The state emergency coordinator will only approve an individual after consideration of all of the circumstances, including the public health risks."
NSW is classed by WA as a medium-risk jurisdiction, denying entry to anyone who cannot secure highly restricted exemptions.
Chief Health Officer Andy Robertson said that would remain the case for "at least two months and possibly more".
He said people wanting to get back from NSW had been given ample time to do so before the restrictions were tightened.
"Obviously if you have very good reason to come back to WA, there might be a very ill family member or a spouse who's having a baby or whatever the case may be, then obviously there are good circumstances," he told Perth radio 6PR.
"But this is not the time to go over for a holiday in NSW, or to go over for work."
WA recorded no new coronavirus cases on Wednesday.
Nine active cases are being monitored, including a returned overseas traveller and a maritime worker who are both in a stable condition in hospital.
A recent four-day lockdown in Perth and the Peel region was traced to a woman who contracted the highly transmissible Delta variant while holidaying in Sydney.
Premier Mark McGowan has accused the federal government of favouring NSW for disaster relief payments, having been denied similar support for casual workers who lost shifts during the Perth lockdown and subsequent restrictions.
A spokeswoman for the premier said some workers had been without work for up to two weeks, which exceeded the Commonwealth's seven-day threshold.
"It's very disappointing the Commonwealth government has chosen to ignore WA workers," she said.
"The prime minister's comments that NSW is the powerhouse of the national economy is utterly wrong, incorrect and it does not reflect the true contribution Western Australia's booming economy is making to the rest of the nation."