The Northern Territory will remain open to NSW despite the COVID-19-ravaged state recording more than 100 new cases.
But Territorians have been warned to come home, with Deputy Chief Health Officer Charles Pain saying the situation could change quickly.
"We're watching whether people are breaching their conditions around lockdown in Sydney," he told reporters on Monday.
Evidence that it's occurring in significant numbers and further community transmission may lead to further restrictions, he says.
"We tend to pull the trigger fairly quickly ... Consider whether you should be in NSW and come home," he said.
Dr Pain said further border restrictions could be imposed on travellers from NSW after the Australian Health Protection Principal Committee meeting on Monday.
Currently, people in 36 NSW local government areas in and around Sydney, which have been declared hotspots by NT Health, are required to get tested and quarantine for 14 days upon arrival in the territory.
Those outside the hotspots can continue to travel to the NT without any restrictions, however, all arrivals must complete a border entry form.
Meanwhile, NT Health has cancelled hotspot declarations for the City of Brisbane and Moreton Bay Region in Queensland.
Test and quarantine directions remain in place for people who have been to a COVID-19 public exposure site in the state.