WELLINGTON - New Zealand Prime Minister Jacinda Ardern said on Monday that the country will shut down in response to the community transmission of COVID-19 in two days.

Ardern announced the country would adopt the most severe response, level four of New Zealand's COVID-19 response system, in 48 hours.

"These decisions will place the most significant restriction on New Zealanders' movements in modern history. This is not a decision taken lightly. But this is our best chance to slow the virus and to save lives," Ardern said.

Level four means schools will close from Tuesday, with only essential services, such as supermarkets, doctors, pharmacies, service stations, in place.

New Zealand confirmed 36 new COVID-19 cases on Monday, which took the total number of cases in this country to 102, according to the Ministry of Health.

"We are all now preparing to go into self-isolation as a nation. Just as you've seen with other countries," she said, adding staying at home is essential and highly effective way to constrain the virus, which will help give the healthcare system a fighting chance.

To stop community transmission which has a lag time, these measures will need to be in place for four weeks, she said.

Over the next 48 hours, every workplace must implement alternative ways of working, people must work from home so that interactions with others are limited, Ardern said.

Essential service workers must ensure physical distancing of staff of two meters, or utilize appropriate Personal Protective Equipment, she added.

Schools will be closed from Tuesday, except to the children of essential workers such as our doctors, nurses, ambulance drivers and police - this will give them time to plan. This will be temporary, and schools will close entirely from midnight Wednesday, the prime minister said.

Air travel and public transport will only be applying to the transport of people undertaking essential services, for medical reasons, and the transport of freight, including ferry services between the North and South Island, after 48 hours, she said.