NSW will further tighten its border with Victoria, with those from the southern state only allowed in for "extremely limited" purposes.
From midnight on Tuesday, a border zone will be set up along the Murray River and all current permits for crossing back and forth will be cancelled.
Residents in the border zone who wish to travel between the states will be forced to reapply for permits under tougher criteria.
People will only be permitted to travel for work, for education if they can't work or learn from home, or for medical care, supplies or health services.
"The growing rates of community transmission in Victoria have us on high alert," NSW Health Minister Brad Hazzard said on Sunday.
"The health advice clearly indicates we need to have stricter border closures in place."
Victoria had three deaths and 363 new cases on Sunday, while NSW recorded 18 new infections in the 24 hours to 8pm on Saturday.
Mr Hazzard said the new protocols will make it harder to obtain a permit and make it easier for the state government to cancel them.
Residents can from Monday afternoon check online to see if their address falls within the new border zone.
If NSW residents travel beyond the border zone into Victoria, they will be forced to self-isolate for two weeks when they return.
Among the changed permit requirements, staff or students of boarding schools or universities must self-isolate for two weeks and obtain a negative swab before attending school.
Seasonal workers from Victoria are also banned from entering NSW.