Covid-19 Response Minister Chris Hipkins says people should prepare themselves for increasing numbers of daily cases.
On Tuesday the number of community cases reached a pandemic daily high for New Zealand of 94.
Hipkins told Morning Report modelling shows the case numbers will double every couple of weeks before levelling out - with different scenarios putting the top figure at either 200 or the high hundreds.
"It's anybody's guess it could be higher than that. I wouldn't want to put a specific number on it."
He said there are signs vaccination rates are starting to have an impact on infections.
School reopening fears
Hipkins, who is also Education Minister. said if Delta was to make it into primary schools, it could lead to widespread transmission of the virus, due to the pupils being too young to be vaccinated.
"One of the things that we're acutely aware of is that in primary school settings, these will quickly become the highest concentration locations of people who are not vaccinated, because primary school students at this point cannot be vaccinated, and that does have significant risk associated with it."
He said primary schools is one of the areas which keeps him awake at night
