Experts concerned about New Zealand's new alert level rules

Experts are warning New Zealand's decreasing restrictions as COVID-19 comes under control in the country are a "cause for concern" among the nation's most vulnerable.

On Monday Jacinda Ardern announced the number of Kiwis allowed to attend gatherings would increase from 10 people to 100 from May 29.

"It's another step in renormalising life as we continue to stamp out the virus," she said.

But Professor Michael Plank from Te Pūnaha Matatini and the University of Canterbury says the decision is a "cause for concern, as it's such a big increase".

"COVID-19 doesn't tend to spread in ones and twos, it tends to spread to a large number of people in one go at big, social gatherings, such as a wedding or bar. If this happens, trying to trace 100 people and all their contacts is a lot harder than if there were just 10," he says.

"As the PM pointed out today, the loosening of restrictions gives New Zealanders more freedom than most other countries have right now. With that increased freedom comes responsibility so, first of all, people should ask themselves whether they really need to hold a large function or attend a big gathering."

Plank is asking Kiwis to remain vigilant as the restrictions ease, including continuing to practice social distancing, good hygiene and record location details on the NZ COVID Tracer app.

"If everyone does this, it will really help our contact tracers track everyone down quickly if we do get a new case cluster at a large gathering."

Victoria University of Wellington clinical psychologist Dr Dougal Sutherland is also worried about the easing restrictions.

"Today's announcement from the Prime Minister indicates a further loosening of restrictions and takes us closer to 'normal'. But normal brings with it many challenges."

He says Kiwis have grown used to their lockdown life and for some people the "new normal" will bring harsh realities.

"We can't return to our old job as it no longer exists. We may have to move house as we can't afford the mortgage. The kids will have to go without, as money is hard to come by. The challenges for this group are obvious.

"As we emerge from the shadow of the coronavirus we, as a country, have a challenge in front of us. Do we continue to show kindness, compassion, and practical support to those who are suffering? Or do we cast off these values as they were only temporary clothes worn in strange, unprecedented times?"

Sutherland says we are experiencing a "crossroad" in New Zealand's history.

"Do we choose to pick up the challenge and move forwards or do we turn our backs on this opportunity?"

New Zealand currently has 1504 confirmed cases of COVID-19 and has only recorded three since May 12.