The prime minister is meeting with state and territory leaders on Friday to discuss further moves including help for renters.

NSW and Victorian leaders are considering full statewide lockdowns if the spike in new cases does not slow.

However, health officials say it could be a week until the effect of a second wave of shutdowns, which began on Thursday, curbs case numbers.

Finance Minister Mathias Cormann has ruled out a UK-style wage subsidy but says the government will announce alternative stimulus measures within days.

Business and unions have urged the government to subside wages to keep people employed during the prolonged crisis.

At least eight regional airlines could collapse within days because of the pandemic unless the government offers financial support.

Overnight, Scott Morrison joined Donald Trump and other G20 leaders in an extraordinary video link-up.

The leaders struck a deal to co-ordinate efforts to tackle the pandemic, collectively pledging $A7.5 trillion to prop up the global economy.

The number of confirmed cases in Australia has risen to about 3000 while the death toll rose to 13 on Thursday.

Most people onboard a German-owned cruise ship off the coast of Western Australia will be sent back to Frankfurt within days, with sick passengers treated in Australia.

Health officials are begging Australians to stay at home if they are sick and to keep their distance from other people even if they're healthy.

Labor has urged the government to put tougher measures in place, with deputy leader Richard Marles saying current steps weren't enough to stop exponential growth in cases.

The Greens are pushing for a full lockdown.

But the government says it doesn't want to rush into tighter measures, given strict restrictions were enacted just days ago.

Senior health official Michael Kidd has reminded Australians to be "absolutely scrupulous" with washing their hands, to keep 1.5 metres away from others and to stay at home when sick.

"Everybody has to do their part in making sure that we are protecting each other, and especially protecting the most vulnerable people in our society," Professor Kidd told ABC News.

Australia has tested more than 178,000 people and deputy chief medical officer Paul Kelly says the rate of positive tests is low, at about 1.5 per cent.

Three Victorian men and one from Western Australia, all aged in their 70s, were confirmed on Thursday as Australia's latest fatalities.

Queensland, South Australia and Western Australia joined Victoria and the ACT in moving school holidays forward to give teachers time to switch to online learning.

Teachers will still be at schools so parents who have essential jobs, such as healthcare workers and supermarket shelf-stackers, can send their children.

But all other students are being asked to stay home.

Millions of masks are expected to arrive in Australia over the coming months.

The nation has already had two waves of business closures this week - leading to thousands losing their jobs - in a bid to stop people gathering in large numbers or in closed spaces.

Thousands more businesses were shuttered on Thursday and many large retailers stood down staff and closed stores voluntarily.

Australian Associated Press