The Northern Territory government has declared Port Stephens in NSW a coronavirus hotspot, imposing tight restrictions on anyone travelling from there to the Territory.
The measure requires anyone from the town, north of Newcastle, into mandatory supervised quarantine for two weeks.
"Anyone who arrives on our borders who has been in a hotspot within the last 14 days has two choices," Chief Minister Michael Gunner said on Thursday.
"Turn around and go home, or go into a supervised facility like Howard Springs for 14 days, and be charged $2500.
"I know that's bad news for other Australians, but it's what needs to happen to keep Territorians safe and that's my top priority."
The new declaration follows a cluster of COVID-19 cases in Port Stephens including some involving school children.
The NT previously named the whole of Victoria and the greater Sydney region coronavirus hotspots, but it is allowing free entry to the Territory for people coming from other parts of the country.