Cases have continued to rise in the last few days, with 162 reported on Monday as quarantine-free travel reopened for fully vaccinated visitors from Aotearoa to Australia.

Of those, 53 people were in hospital, with four in intensive care. Infections are expected to keep rising in modelling of the outbreak released to the media.

As New Zealand battles the spread of the infectious Delta variant of COVID-19, Jacinda Ardern's government has agreed on a November 10 reopening date for retail stores and institutions such as libraries and museums.

"Because of the high vaccination rates in Auckland we can move with greater confidence," Ms Ardern told reporters.

"These decisions are carefully balanced and allow us to release some of the pressure and fatigue that we know exists in Auckland."

The city's limit on the size of outdoor gatherings was lifted to 25 people.

Overall, New Zealand has reported about 6200 cases of COVID-19 and 28 deaths since the onset of the pandemic.

But Ms Ardern said high vaccination rates gave protection to keep down hospital admissions.

"Previously we worked hard to eliminate every case. While Delta has forced us to change our approach, vaccines ensure we have the same goal," she said.

More than 75 per cent of New Zealanders, or about 3.1 million people, have now been fully vaccinated, while 88 per cent have received at least one dose.

However, the government said an increasing number of new cases are among the Maori community, where the vaccination rate is lower.

Australian Associated Press