Deputy Chief Medical Officer Nick Coatsworth says there would be some increases in cases and that restrictions would need to continue until a vaccine for the virus is found.

But he said what was happening in Victoria shouldn't stop other states from going ahead with their plans to ease their own restrictions, because the virus situation was different in each jurisdiction.

Some state premiers are showing uneasiness after Victoria was forced to reimpose some COVID-19 restrictions and delay planned ones for three weeks after recording double-digit increases in cases for five days in a row.

Victoria confirmed another 19 cases on Sunday, making a total of 160 new cases in the past week, up from 35 the previous week. The only other cases reported on Sunday were five in NSW and one in Western Australia.

"It is a timely reminder that in a population that is not immune to the virus ... we will get, from time to time, outbreaks and clusters as we have seen in Victoria," Dr Coatsworth told reporters in Canberra.

"Importantly as well, for those states where restrictions are lifting, that doesn't imply a lifting of our personal behaviour standards that we have become so used to."

That included people maintaining social distancing, excellent hand hygiene, and staying away from others and getting tested if they have symptoms.

"All those elements have been exceptionally successful in controlling COVID-19 in Australia thus far and there is no reason to expect that will be any different into the future."

He said there were only three confirmed cases so far from people who had attended the Black Lives Matter protest two weeks ago, but there was no evidence they had infected anyone else.

More than half of the new Victorian cases since the end of April have come from family members spreading it to their relatives.

The latest figures have led to the Victorian government deciding to extend the state of emergency until July 19.

Some states, including Queensland, have indicated they could retain their tough stance against interstate travel as a result.

Queensland has declared metropolitan Melbourne a hotspot, and anyone coming from those areas would need to quarantine for two weeks if they entered the state. Queensland stopped non-essential interstate travel in late March and is expected to end that on July 10.

"The last thing we want to do is lift the borders, have lots of people come here for school holidays, spread coronavirus in our state, and then force us to go backwards on restrictions," Queensland Health Minister Steven Miles told reporters on Sunday.

"Clearly what's happening in Victoria will be a matter we will need to take into account in those considerations."

Dr Coatsworth said state and territory governments needed to make their decisions on restrictions based on their local epidemiology.

"So it would be unreasonable for WA or Northern Territory or, indeed, Queensland at the moment to be making decisions on their restrictions necessarily with a close eye on what's going on in Victoria because their epidemiology is different," Dr Coatsworth said.

Federal Finance Minister Mathias Cormann said the Victorian clusters should not stop state other states reopening their border as soon as possible.

He noted there had never been a state border closure between NSW and Victoria.

"You don't see there is any issue in NSW as a result of localised outbreaks in Victoria," he told reporters in Perth.

But WA Premier Mark McGowan, who was at an announcement alongside Senator Cormann in Perth, appeared in no rush reopen his state's borders.

"Clearly what has happened in Victoria means that we will take that into account in any decisions we'll make, but like everyone I'm very worried about it when you see these outbreaks," Mr McGowan said.

"Once they get out of control people can die and I don't want to see that come here."

South Australia is due to reopen on July 20 but its government is closely monitoring the situation in Victoria and has not ruled out staying closed.

Australian Industry Group Chief Executive Innes Willox said the reimposition of tighter restrictions in Victoria would batter already fragile business and consumer confidence.

"The economic impact unfortunately will be hard and harsh," he said in a statement.

Opposition health spokesman Chris Bowen said there was still a long way to go in tackling the virus.

"Until this virus is defeated everywhere, it's not defeated anywhere," he said.

There are now 7461 virus cases confirmed across Australia since the initial outbreak. The death toll remains at 102, relatively low by international standards.

Australian Associated Press