A second round of stay at home orders will kick in tonight for parts of Melbourne hit by Covid-19, and the Director-General of Health says similar measures could be used here if needed.
Dr Ashley Bloomfield told Morning Report implementing targeted lockdowns was "definitely something that could happen and we have done some work and are doing further work on if there was a localised outbreak within a suburb, town, city or region what sort of measures should we put in place".
New Zealand had worked closely with Australia since the start of the outbreak, so it would be watching to see how the second lockdown was handled across the ditch, he said.
"We would be looking to use exactly these sorts of measures and approaches [being used in Melbourne] to avoid having to put the whole country up an alert level."
"We don't think there necessarily needs to be zero cases in Australia [for a bubble]" - Dr Ashley Bloomfield
With the second lockdown coming amid continuing interest in a trans-Tasman bubble, Dr Bloomfield said: "The events in Melbourne over the past couple of weeks are both a reminder and do change the likelihood of being able to set up this arrangement in the near future".
The whole idea of the bubble would be to "allow people to travel ... as if they were travelling domestically" and currently, the Melbourne situation was even affecting travel within Australia, Dr Bloomfield said.
However, there had been a lot of work on a potential bubble over the past month and it was continuing, he said.
"We don't think there necessarily needs to be zero cases in Australia [for a bubble], it is a big country so potentially we could have arrangements state by state."
Meanwhile, National Party leader Todd Muller told Morning Report he wanted more transparency from the government around the next phase in plans to reopen the border.
"I am not suggesting you open up with an inability to manage the risk" - National Party leader Todd Muller
"You just heard from Dr Bloomfield that they're reflecting on what the criteria could be, what the conditions are that have to be met in Australia and other jurisdictions before we could consider it but we have no visibility on that.
"I want that because that's critical for us to start planning around what the next three, six, nine months will look like."
While he said he was not advocating for the borders to be reopened right away, it was important to understand how the country would engage with others that had similar or improving Covid-19 strategies.
"But you also must have the capacity as a country to have a conversation around what's next, what does the next phase look like...
"What does the level of presence of Covid need to be in those countries before we would be able to entertain that idea, what would then be required of travellers in terms of pre-travel checks or confirmation that they're Covid-free, would our equivalent systems between the countries accept that?"
Covid-19 in New Zealand
As for the presence of the novel coronavirus in New Zealand, Dr Bloomfield said it was impossible to give an absolute assurance there was no community transmission.
However, he said: "Of the people who left managed isolation between that 9th and 16th [of June] there were the 55 who had left before 14 days, largely for compassionate reasons - they have all been followed up and no cases there, no risk.
"We have also been able to find and test 60 percent of the other folks and remembering it's more than two weeks since they left and they had all completed the 14 days ... and we have done very wide testing in the community.
"You would have seen last week there were over 10,000 tests one day and over 9000 tests another day and there is no evidence of any cases out there, all of our cases are within managed isolation facilities."