The prime minister has attracted criticism from business leaders, health officials and some colleagues for refusing to outline a framework for when the country will reopen.

The budget papers predict a mid-2022 deadline but there are no guarantees.

Mr Morrison warned Australia's relative safety from coronavirus could be compromised if borders reopen too early.

"It's called rushing to failure," he told 2GB radio on Wednesday.

"Australians are demonstrating a great deal of patience and the position we have been maintaining is the sensible one.

"That doesn't mean we're not planning for when we can do it ... but for now and for some time yet we need to play it safe because that's what protects lives and it's also what protects livelihoods."

The prime minister said Australia's relative success against coronavirus did not mean the country was somehow immune from the disease.

Singapore and Taiwan are both battling fresh waves of coronavirus infections despite extraordinary early success.

"The virus is quite an opponent," Mr Morrison said.

Australian Associated Press