Scott Morrison did not go into any details as to the package, but said the Treasury was working closely with other agencies "to address the boost that we believe will be necessary".
"It will be a targeted plan. It will be a measured plan. It will be a scalable plan.
"It will be targeted on the real diagnosis of the economic issue we are looking to confront here.
"We will ensure that we do not make the same mistakes of previous stimulus measures that have been put in place."
Mr Morrison emphasised the difference between the current economic downturn and the global financial crisis of 2008.
"There is no problem with the banking system," he said.
"There is no problem, structurally, with the stability of the economy or things of that nature.
"This is a health crisis which has had serious disruptive impact on the trouble, the movement of people, and of goods around the world."
The Prime Minister also addressed the panic buying which had been reported at supermarkets across the country.
"I spoke to Coles and Woolworths on the way in," he told reporters in Canberra.
"They would send the same message I am sending you today.
"It is important that people just go about their business and their normal processes in a calm manner."
Chief Medical Officer Brendan Murphy said there was "no reason for people to panic buy".
"We do have a very advanced pandemic plan, we are working across every part of the health system to make sure that we are prepared for any eventuality," he said.
"But at this stage, we have small numbers of cases that are controlled and the community can be reassured that there is no reason to change normal behaviours."
The announcement comes ahead of the RBA rates decision this afternoon.
READ MORE: How to spot the symptoms of coronavirus
Source: 9News https://www.9news.com.au/national/coronavirus-stimulus-package-announced-after-serious-market-losses/4a44a905-f234-4361-b7fe-ad2edc7ab1db