Extra COVID-19 testing clinics have opened in Jindabyne and Cooma to tackle the risk of an outbreak as people flock to the mountains for a delayed start to the snow season.
NSW Deputy Premier John Barilaro said the Snowy Mountains were an area of "major concern" due to Victoria's rising number of coronavirus cases, with its school holidays just a week away.
"We know with school holidays, people may be heading to the ski fields for their winter recreation," he told 2GB on Tuesday.
"If Victorians are coming to the Snowy Mountains, you're not just risking the people living in Monaro.
"You're actually risking people living in Sydney, because there's going to be heaps of Sydney-siders up there this weekend skiing and then there could be an outbreak."
Mr Barilaro said test results would be returned within 60 minutes for patients presenting at the Cooma testing clinic.
"We'll be able to pinpoint immediately if there is an issue," he said.
"We're putting all our measures in place, the resort owners are putting in place social distancing. In many cases they're only using 30 to 50 per cent of the resorts."
The ski season opened on Monday with limits of people using chairlifts and caps on patrons. Lift tickets must be pre-purchased so resorts can stick to strict limits.
An outbreak of community transmission in Victoria has posed a new threat to the season, with six areas identified as hotspots of the virus including; Brimbank, Cardinia, Casey, Darebin, Hume and Moreland.
Mr Barilaro said the government would "try to keep the borders open" but urged the community against interstate travel.
"Only travel if you need to. Don't travel across the border if you don't have to. Personal responsibility is at the heart of all of this."
ACT Chief Health Officer Kerryn Coleman has discouraged travel to the Victorian hotspots, but said it was unlikely travel restrictions would be imposed unless "things considerably change for the worse".
