The NSW premier has called for businesses to steer clear of visitors from Melbourne amid an outbreak of COVID-19 cases in Victoria.
Victoria confirmed another 17 cases of coronavirus on Tuesday, taking to 193 the number of new diagnoses during the past nine days.
Premier Gladys Berejiklian has repeatedly criticised interstate travel restrictions and says she will not agree to border closures with any of NSW's neighbour states.
But she has urged against travel to Melbourne, particularly its six current COVID-19 hotspots - the local government areas of Hume, Casey, Brimbank, Moreland, Cardinia and Darebin.
Residents of those hotspots should not be moving around the community, the premier said on Tuesday.
"I call on all organisations not to interact with citizens from Melbourne at this stage," Ms Berejiklian told reporters.
"Have activity elsewhere and I note a number of organisations have already taken on that advice.
"And as for resorts and other locations in NSW, they are at liberty to accept or reject any traveller."
NSW recorded just one COVID-19 case - in a returned traveller in hotel quarantine - in the 24 hours to 8pm on Monday from more than 8000 tests.
Some 3150 COVID-19 cases have been reported in NSW to date, with none in intensive care.
Ms Berejiklian again encouraged NSW residents to seek testing if they felt unwell.
"When back in March we had cases in excess of 200 (per day) in NSW, all of our borders remained open, and we've seen as the number of cases have reduced the ability of our health system to cope with reducing the spread," Ms Berejiklian told reporters on Tuesday.
"As the NSW government and Victorian governments have both said, you should not be moving around the community if you live in one of those hotspots in Melbourne.
"If you are someone in NSW, you should not be going to any of those hotspots, full stop ... (and) you should not be travelling to Melbourne at this time."
Federal Health Minister Greg Hunt said on Tuesday that Australia's international borders would remain closed for "a very significant" amount of time as global coronavirus infection rates accelerate - potentially until a vaccine is secured.
The number of coronavirus infections around the world has exceeded nine million.