The border war between the NSW Premier and her Western Australian counterpart has intensified, after Gladys Berejiklian accused Mark McGowan of closing his state off to preserve his popularity.

On Wednesday, Ms Berejiklian announced travel restrictions in NSW would be scrapped from June 1 and encouraged interstate visitors to book a holiday there.

That prompted an outburst from Mr McGowan, who claimed his government was being “bullied” by the Premier of Australia’s most populous state.

Ms Berejiklian maintains interstate travel will be an important part of Australia’s economic recovery from the coronavirus pandemic, and on Thursday reiterated other states would miss out if they kept their borders closed.

WA, Queensland, South Australia, the Northern Territory and Tasmania have all closed their borders, and are yet to announce a firm timeline to reopen them.

“In fact, I’m sure those premiers are getting more popular in their states for keeping their borders closed,” Ms Berejiklian told ABC News Breakfast on Thursday.

In a recent Newspoll, Mr McGowan was rated the nation’s most popular leader, earning approval from 89 per cent of the WA public.

WA Police and Navy personnel at an intrastate checkpoint south of Perth in April. Photo: AAP

Queensland Premier Annastacia Palaszczuk this week said her state’s border was likely to remain closed until September.

NSW accounts for roughly half of Australia’s more than 7000 coronavirus infections. However, new cases have largely flatlined in the past month.

In the 24 hours to 8pm Wednesday, there were two new cases in NSW, from more than 9700 tests.

Ms Berejiklian said for Australia to move forward economically, the borders needed to come down.

While she said each state “has its views on what should occur”, Ms Berejiklian pointed out that, as international travel ground to a halt during the pandemic, NSW had been the “gateway to Australia”, playing a crucial role in helping people in other states get home.

“The irony is that we have been doing that for all the states for a significant number of months, so we have been supporting them [other states],” she said.

“We proudly say we’re the global city of Australia, we’re the gateway to Australia. And we’ve taken on that role during the pandemic.”

During his broadside on Wednesday, Mr McGowan accused NSW of having an inconsistent coronavirus message.

“NSW had the Ruby Princess – I mean, seriously? And they are trying to give us advice on our borders, seriously?” he said.

“Do you think I should listen to them? I’m not listening to them,” he said.

On Thursday, Australia’s Deputy Chief Medical Officer Paul Kelly said he saw no medical reason to keep state borders closed any longer.