New Zealand's current lockdown measures will remain in place until at least 26 August.
New Zealand will keep coronavirus restrictions in place for another 12 days as authorities work to determine the scale of an Auckland outbreak that has now infected at least 30 people.
Prime Minister Jacinda Ardern announced on Friday afternoon Auckland would remain in Level 3 lockdown, and the rest of the country in Level 2, until 11:59pm on 26 August.
Ms Ardern said the extension of the lockdowns would buy authorities more time to stop the Auckland cluster from growing.
"Our current expectation is that by this time, the perimeter of the cluster will be identified, will be isolated, and we can move to Level 2 in Auckland with confidence," she told reporters in Wellington.
Ms Ardern said the genomic sequence of the virus from the current outbreak is not the same as that from community cases recorded during the country's first outbreak.
“This suggests this is not a case of the virus being dormant or being a burning ember in our community. It appears to be new to New Zealand.”
The government would review the restrictions on 21 August, Ms Ardern said, adding there was "nothing to suggest" any area in the country needed to move back to a harsh Level 4 lockdown.
Earlier on Friday, New Zealand's Chief Health Officer Ashley Bloomfield announced 12 new coronavirus cases and one probable case.
Positive tests have been recorded at four schools and at least two businesses, as officials deploy a "rapid response" contact tracing effort.
Dr Bloomfield said of the 13 new cases, all but one of them is linked to the initial cluster of four in Auckland.
"For the 13th case - and that person is currently in hospital - the link is still under investigation," he told reporters.
"It is the most recent case we have been informed of, and work is underway on that one."
The new cases reported on Friday bring the total number of active cases in New Zealand to 48, with one person in Auckland Hospital.
First identified on Tuesday, the new Auckland cluster - comprising four cases in one household - has thrown New Zealanders back into the clutches of the pandemic.
Meanwhile, Australia's top health official has labelled New Zealand's decision to lift coronavirus restrictions after seemingly squashing the disease as "dangerous".
"To go right back to a pre-COVID state makes them extremely vulnerable," acting chief medical officer Paul Kelly told the Senate's coronavirus inquiry on Friday.
He said New Zealand's fresh outbreak showed why well-performing Australian states must remain vigilant.
With Naveen Razik and AAP.
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