Strict Australian domestic border closures 'required and necessary': Minister

CANBERRA - Australia's Health Minister has declared that domestic border closures were "necessary" to prevent the spread of COVID-19.

New South Wales (NSW) will close its border with Victoria from 12:01 am on Wednesday amid a spike in coronavirus cases in the latter state.

Despite the federal government having repeatedly called for domestic borders to be re-opened, Health Minister Greg Hunt told Australian Broadcasting Corporation (ABC) on Tuesday that closures were "always planned" in the event of an outbreak.

"Right from the start in February we've talked about the concept of rings of containment -- whether it's been suburbs, broader areas such as northwest Tasmania, or when it's required to take that step," he said.

"Now is the moment when we believe that step, for the first time, is required and necessary and it relates specifically and exclusively to the challenges that Victoria is facing. I know it's difficult and I know it's challenging."

"We have been through this already. In March, what we saw was that -- and in April -- Australians had difficult restrictions put in place. We were able to deal with it, we were able to rise to it, and we were able to flatten that curve," said the minister.

The border closure was announced by the NSW government on Monday when Victorian authorities revealed that there were 127 new confirmed cases of COVID-19 in the state -- a record high daily increase.

It will be the first time that the border between Australia's two most populous states has been closed in about 100 years.

The Department of Defence on Monday night confirmed that up to 500 Australian Defence Force (ADF) personnel would be deployed to enforce checkpoints at border crossings.

"This assistance is in addition to approximately 200 ADF medical personnel currently supporting public health testing initiatives as part of the Operation COVID-19 Assist," a Defence spokesperson told News Corp Australia.

"About 190 of these members are involved in the Victorian government's public health testing initiatives, with the remainder involved in planning and headquarters roles."

In a move that has further isolated Victoria from the rest of Australia, Northern Territory (NT) Chief Minister Michael Gunner has announced that residents of the greater Melbourne area will continue to be subjected to mandatory 14-day quarantine periods when the NT border re-opens on July 17.

Gunner said on Monday night that he had made the decision that all of Melbourne is a hotspot.

"These rules apply to everyone, not just Victorians. That includes Territorians. Territorians should reconsider any planned travel to any location in Melbourne in the near future," he said.

"Right now, the problem is confined to Melbourne, but we will keep a watching brief on the rest of Victoria. Hotspot areas may be added prior to July 17, depending on the health advice."

"However, I want to make clear that no area in the greater Melbourne region will be removed from the list prior to July 17. They will stay shut off from the Territory until further notice," said Gunner.

As at 3 pm on Monday, a total of 8,586 cases have been reported in Australia, including 106 deaths, and 7,420 have been reported as recovered from COVID-19. And the number of new cases in last 24 hours is 140, according to figures from the Department of Health.

The department also said that over the past week, there has been an average of 90 new cases reported each day. Of the newly reported cases, the majority have been from Victoria.