Australia's Northern Territory (NT) has opened its domestic borders for the first time since March.

On Friday, the NT's borders were reopened to travellers from the rest of the country, except for those from coronavirus hotspots in Victoria and Sydney, after almost four months of hard line border controls.

The NT has had only 31 confirmed cases of COVID-19, by far the fewest of any Australian state or territory, and has made progress in easing coronavirus restrictions.

Michael Gunner, the NT's Chief Minister, urged visitors and Territorians to continue following physical distancing guidelines to prevent a spike in cases.

"We've all got a big job to do and we can't slack off," he said.

"I'm asking you to keep digging deep, we have to stay the best and for many of us that means getting back in the habit. We aren't the best by luck, we're the best because of you. Get back in the habit of keeping your distance, not shaking hands, good hygiene, staying home if you're sick and getting tested."

The NT's borders were closed on March 24 in a major blow for the region's tourism operators.

Alex Bruce, the chief executive officer of Hospitality NT, said that after nearly four months the tourism and hospitality sectors were ready to welcome new arrivals.