New Zealand Prime Minister Jacinda Ardern will join a National Cabinet meeting with Australian leaders to discuss a “trans-Tasman bubble” as both countries experience a reduction in the spread of the coronavirus.

The scheduled dial-in cameo meeting on Tuesday with state and federal leaders comes as New Zealand cautiously celebrated a day without new COVID-19 cases for the first time since the peak of the pandemic.

The National Cabinet formally invited Ms Ardern to join its meeting on Tuesday, which will include a discussion about the contact tracing apps both countries are using.

Prime Minister Scott Morrison flagged the intention to add Ms Ardern to the meeting during his regular discussion with her last Thursday.

Australia and New Zealand have taken slightly different approaches to reducing the spread of COVID-19 but have enjoyed similar success.

Australia has 6801 confirmed cases of the coronavirus with 95 deaths while New Zealand has 1487 cases with 20 deaths.

It’s expected the meeting will advance early discussions on a so-called “trans-Tasman bubble” that would allow the relaxation of border restrictions between the citizens of two countries and allies.

Ms Ardern told New Zealand media on Monday that she had accepted the “unprecedented” invitation.

“It … highlights what has happened with the cooperation at a state level in Australia and also the mutual importance of our two countries and economies to each other,” she said.

“Both our countries’ strong records on fighting the virus has placed us in the enviable position of being able to plan the next stage in our economic rebuild and include trans-Tasman travel and engagement in our strategy.”

She said her discussions with Australian leaders had led her to believe both countries were considering similar timelines for reopening. A “trans-Tasman bubble” offered advantages for both nations.

“Don’t expect this to happen in a couple of weeks,” she said.

“We need to make sure we lock in the gains that all New Zealanders have helped us achieve, and make sure we have health precautions in place to make sure we do this safely and well.”

Ms Ardern’s invitation to join a National Cabinet meeting follows her telephone chat with the Queen last Tuesday, after which she took to social media to declare it was “such a treat” to speak to the monarch.

People are still able to enter Australia under exceptional circumstances, like the New Zealand Warriors rugby league team, who touched down in Tamworth on Sunday.

NRL clubs will officially resume training on Wednesday ahead of the planned season restart on May 28.

Just four Kiwis currently require hospital treatment for the virus, with none in intensive care.

The announcement will sharpen local hopes for a reduction of Australia’s lockdown to allow for more recreation, travel, and the return of retail business.

National Cabinet will assess this week whether Australia’s restrictions might loosen further from May 11.

However, acting immigration minister Alan Tudge said reopening international borders was still a long way off.

“The main source of infections has been across those borders,” he told ABC radio on Monday.

Treasury is forecasting an 85 per cent drop in migration in 2020-21.

NZ thanks Australia for opening its borders

NZ’s Deputy Prime Minister, Winston Peters, thanked the Australian government for opening its border to the Warriors, calling it a forerunner to closer travel ties between the two countries.

Mr Peters said the travel relationship would be viable only if it did not require a 14-day quarantine period at either end, something the Warriors have begun in Tamworth.

“The Warriors’ participation in the NRL in Australia shows that a trans-Tasman bubble could work seriously well,” Mr Peters said.

“Australia and New Zealand are two of the most integrated economies in the world. The idea of a bubble with Australia was floated two weeks ago, and this is an example of the sort of action that could happen within it, while always ensuring the protection of public health.”

“Officials in both countries are considering all aspects of the trans-Tasman concept, and planning how this could happen more broadly.”

Victoria’s cases spike as schools begin staggered return

Meanwhile, the coronavirus outbreak at a Victorian abattoir has highlighted the volatility of the disease as governments consider relaxing social and economic clamps.

Cedar Meats, in Melbourne’s west, is behind 19 of the state’s 22 new cases. There are 34 coronavirus cases linked to the meat works.

A Sydney school was closed on Monday when a student tested positive, just one day after a Melbourne campus was shut because a teacher contracted the disease.

In Queensland, the staggered path back to school has been outlined with kindergarten, prep, years 1, 11 and 12 to return to classrooms on May 11.

Schools are expected to be fully operational from May 25 provided the number of cases detected remains low across the state.

Chief medical officer Brendan Murphy has warned it will be a slow road back to reality, with health authorities wary of a fresh round of infections.

“The lessons we have learnt from overseas is that if you go too quickly and open up things too quickly, you can get a second wave,” he told reporters.

-with AAP