Jacinda Ardern flexes her Hitlerian muscles, moving to take New Zealand to a Level 4 State of National Emergency, which means:

Once level 4 is in place, all New Zealanders not in essential services will be asked to stay at home.

"I understand that self isolation is a daunting prospect," Ardern said.

"You can leave your home for fresh air, a walk, exercise. To take your children outside. But remember the simple principle. It must be solitary.

"We are asking that you only spend time with those you are in self isolation with. And if you are outside, keep your distance from others. That means 2 meters at all times.

Public transport will only be open to those working in essential services, for medical reasons, or to move essential goods – including ferry services between the North and South Island.

"The situation here is moving at pace, and so must we," Ardern said.

"Get your neighbour's phone number, set up a community group chat, get your gear to work from home, cancel social gatherings of any size or shape, prepare to walk around the block while keeping a two-metre distance between you.

"These measures will be in place for four weeks at this point."

Ardern said regions could then have alert level 4 eased, depending on how Covid-19 was present in those areas.

"If you hang out with that friend at a park or see that family member for lunch, you risk spreading Covid-19 and extending everyone's time in level 4."