Queensland may delay opening up to NSW if health officials can't quickly source three mystery COVID-19 cases in Sydney, as Prime Minister Scott Morrison blasts the Palaszczuk government for keeping the border closed.
NSW has about a day left to find the source of the unlinked cases, which were diagnosed in the community late on Tuesday.
If they can't, Queensland may consider resetting the 28-day border clock but it is not an automatic result and will be reviewed at the end of October.
Premier Annastacia Palaszczuk says she remains on "high alert" and is "not ruling out anything" when asked about reopening the border, which was tentatively planned for the end of the month.
"We are going to be looking at those cases. I'm looking forward to seeing what the premier of New South Wales has to say," she said while campaigning on Thursday in Townsville.
"We hope that NSW gets on top of those cases, very very quickly."
Ms Palaszczuk said it should be possible for NSW to reach 28 days without community transmission, as other states had done.
The border between the two states has been closed since August 8, when Queensland set NSW a target of 28 days of unlinked community transmission before it fully reopened.
NSW on Thursday said it now had eight new locally acquired virus cases, including the three flagged on Wednesday, ending the state's run of 12 consecutive days without community transmission.
Under nationally agreed guidelines, NSW has 48 hours to link community transmission cases to a known cluster for the clock to keep ticking.
Queensland Health Minister Steven Miles said if it takes longer it increases the risk the sources may have been infectious in the community while unidentified.
"That's why it is important we find those links quickly and if we don't the risk of a further outbreak is greater," he said.
Mr Miles previously said NSW had until Thursday night to scientifically link the cases or the border clock could be reset.
Earlier, Prime Minister Scott Morrison took aim at Queensland and Western Australia over their strict border closures, saying they should only be in place for health reasons.
He criticised Ms Palaszczuk for keeping borders closed, saying more people in NSW had returned to work than in Queensland.
"We need Queenslanders back in jobs, I want to see Queenslanders back in jobs," he said.
Meanwhile, police have ordered 14 Victorian amusement show support staff to leave Queensland after they travelled to Mackay in trucks using incorrect border passes.
All the workers quarantined and tested for COVID-19. They returned negative results.
Queensland recorded no new cases of coronavirus in the 24 hours to Thursday morning.
There are just four active cases in the state and 6729 virus tests were completed.