On Monday the nation of 4.8 million recorded its first day with no new cases of coronavirus.
As Ms Ardern prepares to loosen the lockdown, she attended part of Australia’s Cabinet meeting via videolink to discuss a possible future travel arrangement between the neighbours.
Australia and New Zealand have for more than a month closed their borders to all non-citizens and imposed mandatory quarantines on anyone returning home from overseas.
Both countries have a COVID-19 mortality rate of just 1 percent – well below most other countries.
A total of 1,486 cases have been recorded in New Zealand and just 20 deaths.
And Australia, which has a population of 24.9 million, has confirmed 6,847 illnesses and has a death toll of 96.
Ms Ardern and Australian Prime Minister Scott Morrison discussed the idea of a “trans-Tasman bubble” which would allow for travel between the two countries and without quarantine.
Ms Ardern became the first world leader to join an Australian Cabinet meeting in more than 60 years when she took part in the talks on Tuesday.
Ms Ardern said the conversations centred on a “bubble of sorts between us, a safe zone of travel”.
She added that there was “a lot of work to be done before we can progress…but it’s obviously been floated because of the benefits it would bring”.
When asked about her country’s tourism industry, which has suffered heavily from the lockdown, Ms Ardern was clear that there would be no let up in the near future.
Ms Ardern said leaders would not roll out the travel plan until they are sure coronavirus would not spread between the two countries.
“When we feel comfortable and confident that we both won’t receive cases from Australia, but equally that we won’t export them, then that will be the time to move,” she told reporters in Wellington.
“Neither of us want cases of COVID coming between our countries.”
Rules on social distancing have been eased slightly in New Zealand and in some Australian states and territories but restrictions on large gatherings and non-essential travel remain.
As the Kiwis flatten the curve, Ms Ardern has vowed to completely eliminate the pathogen from the tiny country.
Qantas Airways Ltd Chief Executive Alan Joyce said regular flights between Australia and New Zealand could begin soon after domestic routes were reopened.
He said: “It could be a very good model for the international market opening up in phases.”
Qantas is currently operating only 5 percent of its pre-crisis domestic passenger network and 1 percent of its international network.
Qantas is Australia’s largest airline.