The news comes as the territory has just hit the vaccination milestone of having 80 per cent of its eligible population aged over 16 fully vaccinated against the virus.
Chief Minister Michael Gunner said the territory was now preparing for “its biggest step” towards COVID-freedom so far — the opening of its borders on December 20.
From then, all fully vaccinated arrivals — regardless of where they come from — will not have to quarantine.
“The key question will not be where you have come from but whether you are fully vaccinated or not,” Mr Gunner said.
He warned arrivals would have to be tested for the virus.
“Anyone planning to come to the territory, left in no doubt, you will have to get COVID tested before you get here and after you arrive you,” he said.
Travellers will be required to have evidence of a negative PCR test 72 hours before arriving in the territory.
A second test will have to be taken within the next 72 hours, and a final test will have to be taken six days after arrival.
Arrivals will need to stay in a high vaccination zone for 14 days from when they arrive in Northern Territory.
Unvaccinated travellers will remain banned from entering the territory unless they are returning Territorians, have an exemption, or are under 12 years old.
Currently, arrivals to the Northern Territory from a COVID-19 red zone, which includes Victoria, New South Wales and the ACT, must undertake seven days of home quarantine.
Northern Territory COVID-19 outbreak
The territory has recorded three new cases of COVID-19 today. One is an unvaccinated teenage girl who is a household contact of a previous case.
The second infection is a fully vaccinated woman in her 80s who was in home quarantine.
The third is a fully vaccinated man in his 30s who arrived from Sydney after having been overseas.
Mr Gunner said authorities had concerns about the area of Katherine, leading to residents being legally required to undergo a COVID-19 test.
“There is an area of largely unvaccinated people which have spent a substantial amount of time together. We decided this morning to put in more intensive testing,” he said.
“We will be going door to door to make absolutely certain where the virus is. It would be a legal requirement to get tested. We are being as targeted as we possibly can.”
Greater Katherine, Binjari and Rockhole all exited lockout at midday yesterday.
A mask mandate remains in place in the communities until December 15.