As Victorian COVID-19 cases continue to spike, NSW Premier Gladys Berejiklian has urged residents to not travel to Melbourne and surrounding hotspots as both states head into the school holiday period.

Speaking to media on Monday, Ms Berejiklian said that while she would not be closing the NSW border with Victoria, residents should not be travelling to the southern state “unless it is absolutely essential”.

“The border between New South Wales and Victoria will continue to stay open,” she said. “However, as is consistent with the health advice from Victoria, and also from New South Wales, nobody from New South Wales should be travelling to those hot spots at this present time.”

“People should consider whether they should be travelling to Melbourne at this point in time while community transmission is where it is. Reconsider your plans. Reconsider what you’re doing. But certainly, Melbourne is a discretion. We would recommend people not at this stage travel to Melbourne unless they have to.”

Despite Premier Gladys Berejiklian’s persistent criticism of interstate travel restrictions imposed by the likes of South Australia and Queensland, Deputy Premier John Barilaro said earlier on Monday that NSW was watching the Victorian situation closely and didn’t reject the idea of interstate travel restrictions. Mr Barilaro admitted Victoria’s spike in COVID-19 cases was “worrying” and “a real threat”.

“Maybe some sort of limits around travel, but maybe not closing the border as a whole … it’s more about who’s coming across the border and what we will do about it,” Mr Barilaro told the Seven Network on Monday.

Victorian Health Minister Jenny Mikakos on Sunday announced a four-week state of emergency extension until July 19, with Monday’s planned easing of restrictions postponed and gathering restrictions re-tightened.

A spokeswoman for Ms Berejiklian said “NSW will continue to monitor the health situation in Victoria and nationally”.

Meanwhile, Queensland is gearing up to reopen its borders in the second week of July, but the potential second COVID-19 wave in Victoria places the timeline in jeopardy.

Queensland Health Minister Steven Miles said the government’s intention was to reopen the borders when the next round of restrictions are eased on July 10 but Victoria’s coronavirus concerns could delay that.

“The last thing we want to do is lift the borders, have lots of people come here for school holidays, spread coronavirus in our state, and then force us to go backwards on restrictions,” Mr Miles told reporters on Sunday.

“Clearly what’s happening in Victoria will be a matter we will need to take into account in those considerations.”

Speaking to media on Monday, Queensland Premier Annastacia Palaszczuk said she has “concerns” about Victoria as her government prepares to consider the reopening of state borders.

“The AHPPC (Australian Health Protection Principal Committee) has also said they have concerns about Victoria and I have concerns about Victoria,” Ms Palaszczuk said. “The Health Minister has concerns about Victoria.”

Queensland’s borders have been effectively shut since late March to stymie the spread of COVID-19.

The state recorded zero new cases again on Monday and has not been adversely affected by a Black Lives Matter rally two weeks ago which drew some 30,000 protesters.

“Fortunately, we can now say that having seen more than two weeks pass since that rally, we don’t believe anyone contracted coronavirus at the rally,” Mr Miles added.

“The last thing we want to do is lift the borders, have lots of people come here for school holidays, spread coronavirus in our state, and then force us to go backwards on restrictions.

“Clearly what’s happening in Victoria will be a matter we will need to take into account in those considerations,” Mr Miles said.

On Sunday, Victoria recorded another day of double-digit cases. The spike in COVID-19 cases in Melbourne prompted Queensland’s Chief Health Officer Jeannette Young to include all 31 local government areas in Greater Melbourne as well as bordering areas of Murrindindi, Mitchell, Moorabool, Macedon Ranges and Greater Geelong as hot spots. The only other cases reported on Sunday were five in NSW and one in Western Australia.

It means Victorians can expect to spend two weeks in confinement if they do step foot in Queensland.

Australia’s chief medical officer has warned Australians against travelling to and from Victorian coronavirus hot spots as the state grapples with an outbreak.

Professor Brendan Murphy says some Victorians have been complacent but experts are confident the spike will be brought under control.

But he said it was unlikely the new cases were related to recent protests, telling the ABC it was mainly families who weren’t taking social distancing seriously.

“We’re asking people to respect the public health situation and change their behaviour accordingly,” Professor Murphy told the ABC on Monday.

The Australian Health Protection Principal Committee says outbreaks have been identified in the local government areas of Hume, Casey, Brimbank, Moreland, Cardinia and Darebin.

“The AHPPC strongly discourages travel to and from those areas until control of community transmission has been confirmed,” the committee said in a statement on Sunday.

Prof Murphy also urged Victorians from the coronavirus hot spots to avoid travel to regional areas where there are no cases.

He said the protocols on hygiene, social distancing, and staying away from others if showing symptoms should stay in place.

West Australian Premier Mark McGowan has also remained cautious about reopening his state’s borders, despite federal Finance Minister Mathias Cormann calling for states to end closures.

“Clearly what has happened in Victoria means that we will take that into account in any decisions we’ll make, but like everyone I’m very worried about it when you see these outbreaks,” Mr McGowan said.

“Once they get out of control people can die and I don’t want to see that come here.”

There are now 7460 virus cases confirmed across Australia since the initial outbreak. The death toll remains at 102, relatively low by international standards.

A new report from the Grattan Institute has suggested keeping state borders shut amid the coronavirus pandemic could help in stopping the spread of the virus.

The advice goes against the guidance coming from the Federal Government to allow people to travel between states, with state and territory leaders being urged to open up their borders.

The report “Coming out of COVID Lockdown: The next steps for Australian health care” suggests that as Victorian cases surge, other states could be at risk of people bringing coronavirus into their states.

“We know that people are asymptomatic for a while when they are infectious,” Stephen Duckett, who authored the study, told the ABC.

“If they want to come to Queensland or Western Australia, they should be quarantined for two weeks, just as people coming into Australia are quarantined.”

Mr Duckett, who is the health program director at the Grattan Institute has also backed the “travel bubble” idea where people from some states can travel to other states where infection rates are lower.

“If it is safe to allow people from New South Wales to come in, people from New South Wales should be allowed to come in because the tourism industry is very, very important in Queensland,” Mr Duckett said.

“But if it’s not safe and it runs the risk of COVID-19 escalating again and we go back into this exponential growth phase, it’s just not worth it for them to open their borders.”

– with AAP