LIVE: The country will remain at the red Covid-19 traffic light setting says Prime Minister Jacinda Ardern.

Ardern made the announcement at today's post-Cabinet media briefing from about 4pm.

Ardern says the rolling average of cases had declined 36 per cent in the two weeks since the government refined the traffic light system.

There had been early data showing an uptick since mid-March in people visiting places of retail and recreation in Auckland, as well as more people returning to workplaces, she says.

While cases were dropping in Auckland, Wellington and Tairāwhiti others regions like Canterbury, Northland and Waikato were not experiencing the same drop. Hospitalisations in some District Health Board regions were not expected to peak until mid- to late-April.

"So for now, New Zealand will remain at red," says Ardern.

"I know there is an eagerness to move to orange, but we are still frankly amid an outbreak and there is still pressure across our hospital network.

"Public health advice is that now is not the time to ease restrictions and drop to orange," says Ardern. "For now NZ will remain at red

Ardern says the government does not want to move too quickly and lose the progress made.

"It's less about the case numbers and more about the hospitalisations."

Asked why Auckland cannot move to orange when cases are falling, Ardern says while we are seeing a decline in hospitalisations, "it is off a high base, the numbers are still relatively high, the pressure on our system is still there, we want to make sure that we're in the best possible position and we don't lose the gains we've worked so hard for".

"We've always said that there is the possibility of moving regions to different levels at different times ... but as we've said, Auckland has made significant progress but we do still have a relatively high hospitalisation rate."

"We need to look after our healthcare workforce."

The country needed to help the health system recover and be ready for the expected winter surge, Ardern says, requesting that people get boosted.

"Unvacccinated and people that are not boosted make up a disproportionate number of people in our hospitals. More than 9900 people are due their booster today, please get your booster as soon as you can."

She notes vaccine passes would no longer be required from midnight tonight, although businesses could continue using them if they wished.

The next review of the traffic light settings will be on Thursday April 14.