Large events across Canberra and Australia won't go ahead after Prime Minister Scott Morrison advised against organised non-essential gatherings of more than 500 people continuing after Monday.
Australians have also been advised to reconsider all international travel due to the spread of COVID-19.
The beefed up advice doesn't include schools, universities public transport or airports, Mr Morrison said in Sydney on Friday.
While the start-date of Monday has been criticised by Labor's health spokesman Chris Bowen, it has been reported that the advice to avoid holding such events start on Monday to avoid panic as people left work on Friday evening.
Chief Medical Officer Brendan Murphy said the announcement by the Prime Minister was the same as the advice he had given to the leaders of the states and territories, and was based on medical advice around the difference between casual exposure and sustained contact.
"We have seen increases in numbers every day and we feel that they will be at such a point over coming weeks that it's time to take precautionary advance measures to limit those large events where the incidence of transmission can be supported," Professor Murphy said.
"We're not suggesting that people should interrupt their normal daily work. It's just avoiding those particular circumstances where transmission can be accelerated."
Further details about how the advice will be implemented will be worked out over the weekend, Mr Morrison said.
A new national cabinet, including the Prime Minister, premiers and chief ministers will meet on Sunday, and then at least weekly, to respond to the public health crisis. The national cabinet will be advised by the chief medical officer as well as state and territory health officials and a new the "National Coordination Mechanism" convened by the Department of Home Affairs.
"As we slow [the spread of COVID-19], as we manage it, that ensures that the national health system, the health system run by states and territories, will be able to accommodate the increasing demands we'd expect to see as a result of the coronavirus spread throughout Australia," Mr Morrison said.
Mr Morrison defended the decision to delay the start of the advice until Monday, saying it was what was needed.
It is hoped that the measures will slow the spread of the disease and allow the health system to better cope with the numbers of people expected to be infected.
All travellers have been told to re-consider all non-essential travel overseas.
"Overseas travel has become more complex and unpredictable," a statement from Mr Morrison and Professor Murphy said.
The ACT announced its first case of COVID-19 on Thursday, while NSW has 92 confirmed cases and is investigating almost 2000 more cases.
Victoria announced nine new cases on Friday, including the state's first case of community transmission.
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