Prime Minister Jacinda Ardern gave an update on alert level 2, stamping out Covid-19 and how to get the economy moving again.

Ardern was in Rotorua yesterday, and she said it was pleasing to see people outside with cafes full and people abiding by rules.

She said the best thing we can do for the economy is to keep on top of the virus.

"We do intend to keep phasing in additional activity under level 2 when the evidence shows we can with low to little risk of further outbreaks."

"Descend can be more dangerous than the climb," Ardern said.

She said Covid-19 is still in the community.

"One case can become 90, and it would only take a few cases of those for us to go back into lockdown."

Ardern said the data suggests the approach we've taken so far is right.

The latest cases represent "the long tail of Covid", she said.

She said he last case where the source was unknown was in early April.

"We've had three full transmission cycles with no new cases of community transmissions recorded in NZ," Ardern said.

But she reiterated that the virus was still present in New Zealand and there was still work to be done, and there will be ongoing management of risks.

Rapid contact tracing, surveillance and testing, staying home if sick, tight measures at the border, physical distancing and regular hand-washing are part of those risk management's.

"Amendments to the border rules can occur at any level also, so it's possible to have a trans-Tasman bubble at level 2," she said.

Bars and clubs will reopen tomorrow but with strict level 2 measures.

Ardern said she's satisfied that businesses are prepared for reopening and encouraged people to support local places.

On bars reopening she said: "I know that this time has been incredibly tough... I wish them every success as we look to rebuild as a country and my hope and expectation is that everyone supports them to do that safely."

Ardern said she understands everyone will want to return to 'normal'.

Cabinet will consider increasing the size of gatherings on Monday, currently gatherings are limited to up to 10 people.

If data continues to show positive low levels of cases then that will give them further confidence to increase the size of gatherings under level 2, Ardern said, including for religious places.

"I envisage we will stay in level 2 until the Director-General of Health has the confidence that we can de-escalate further."

Changes will be reviewed every two weeks, she said.

"We do not have to move down a full level in order to wind down restrictions."

Ardern said the expectation for level 1 is that the basic public health measures will continue and there will be some restrictions around the border. It's not status quo, so there will be parameters around it.

A lot the things that inhibit normal business activity will be removed at level 1, she said.

Asked about options for mass gatherings in future, Ardern said they want greater control of any risks in the early phases.

She said the approach so far has been to phase into bigger numbers on gatherings, based on the guidance of the Director-General and the evidence.

If a decision is made on Monday then the changes could be expected in the following 48 hours from there, Ardern said.