Scott Morrison has declared all options should be on the table regarding further restrictions in Victoria after another record day of coronavirus infections.
The state recorded 532 new cases on Monday, with six more deaths taking the national toll to 161.
The prime minister said it was premature to be making calls about a harsher lockdown, but stressed it was important to keep all options open.
Melbourne and Mitchell Shire’s second wave of restrictions will remain in place until August 19.
But with new cases of coronavirus continuing to surge, there are serious doubts about the end date.
Mr Morrison agreed with Victorian Premier Daniel Andrews that making face masks mandatory was effectively an escalation of restrictions.
“He will take advice and make assessments, I would think, over the next week or so about what further may be required at the end of the period that he’s set out,” he told reporters in Sydney on Monday.
Mr Morrison called for patience as health authorities deal with significant levels of community transmission.
“That will take some time to get on top of and that is what the actions are directed to addressing right at this very moment,” he said.
Five-of-the-six latest deaths were from outbreaks in aged care, with the sector now linked to hundreds of cases across Victoria.
Australia experienced its deadliest day of the pandemic on Sunday after 10 Victorians died.
Seven of the deaths were linked to nursing homes.
“When community transmission occurs with COVID-19, the aged care sector will all be impacted,” Mr Morrison said.
The federal government is working with state authorities to transfer residents with coronavirus to hospitals and ensure strict infection control.
National stockpiles of personal protective equipment are being drawn on for aged care.
Deputy Chief Medical Officer Nick Coatsworth believes it will be some time before new case numbers flatten in parts of Victoria where the virus is now embedded in the community.
“There will be light at the end of the tunnel. But those day-on-day numbers now are still concerning,” he told the ABC.
Dr Coatsworth implored Melburnians to wear masks and abide by restrictions.
“If we are all in this together then the light at the end of the tunnel arrives quicker. That is absolutely certain.”