Prime Minister Jacinda Ardern has announced Auckland's lockdown has been extended for 12 days and the rest of the country will remain at alert level for 2 for the same period.
This will bring the total number of days spent at the current alert level settings to 14 days.
"There are signs we have found this outbreak relatively early," Ardern told reporters on Friday.
Auckland went into alert level 3 lockdown at midday on Wednesday and the rest of New Zealand into level 2 after four new cases of community transmission in south Auckland were announced.
Since then more cases have emerged, bringing the country's total cases of community transmission to 30. Of them, 28 are in Auckland and two in Tokoroa.
All are linked to the same cluster.
Ardern said an extension of Auckland's current lockdown is what's required.
"There is nothing to suggest that we need to move to a level 4 lockdown at this stage."
The earliest sign of the outbreak is being centred around a person at the Americold cool store who became ill on July 31.
Ardern said there is nothing linking the cluster to the border at this stage.
The current settings will be reviewed on August 21, while Cabinet has also agreed in principle to extend the wage subsidy scheme nationwide.
Director-General of Health Dr Ashley Bloomfield told reporters the public's swift move on the latest outbreak has been encouraging.
New Zealand's contact tracing systems are a lot more advanced this time around, he said.
He said case patterns in the coming days will be vital.
"Partly it's about the number and also geographical containment, and whether those cases or their close contacts have been in settings where there could have been further spread like churches or schools."