People visiting the ACT from Melbourne coronavirus hot spots will need to quarantine for 14 days at their own expense or return home immediately.
As national institutions reopen to the public in Canberra, the territory government has issued a new public health direction.
Anyone already in the ACT who has been in a Melbourne hot spot has been told to quarantine for two weeks, even if they do not have coronavirus symptoms.
People coming into Canberra from Melbourne must monitor themselves for signs of the virus and passengers on inbound flights must show identification on arrival.
Anyone who refuses to comply will face fines.
Canberra residents have been told not to plan any visits to the Melbourne suburbs under a reinstated coronavirus lockdown and reconsider all non-essential travel to the city for the foreseeable future.
"The situation in Melbourne is concerning and has evolved quickly in the past week," ACT Chief Health Officer Kerryn Coleman said on Friday.
"We ask that people respect the direction and not travel to the ACT from the identified hot spot areas of Melbourne."
Parliament House will reopen to the public on Saturday after the Australian War Memorial and National Gallery of Australia began welcoming guests again.