There are nine new cases of Covid-19 today - one in the "marine engineer cluster" and eight in managed isolation.

Seven of the cases in managed isolation are among the fishing crew in Christchurch, the other person arrived from Iran.

The other new case was a close contact of the marine engineer who is believed to have tested positive while working on a ship that arrived in New Zealand from overseas.

The total number of active cases in New Zealand is 66.

Director general of health Ashley Bloomfield said he was feeling comfortable that level 1 was the right setting and the cluster is well-contained.

Health Minister Chris Hipkins said at this point the cluster wasn't causing him heightened levels of anxiety "just usual levels of anxiety".

Bloomfield said data from the push notification sent about Auckland pub The Malt - where a contact of the marine engineer visited - showed a very low number of people had signed in.

There would be enforcement issues with making it mandatory to sign in as it would be resource-intensive having someone standing at the door ensuring people were signing in, said Hipkins.

But he didn't rule out the option in the future, possibly under higher alert levels.

Hipkins said the last thing they wanted to do was be heavy-handed which could mean people would start rebelling.

There will be a "very intensive" campaign over the next 72 hours to encourage Kiwis to use the app.

"The more we scan, the safer we'll be," Bloomfield said.

Asked about a person who was at The Malt who has refused to be tested, Bloomfield made a personal appeal for him to be tested but there were no legal grounds for them to be forced to.

Bloomfield reminded the media not to doorknock close contacts of Covid-19 cases.

He reminded everyone it was free to get tested, wherever you're tested.

Bloomfield repeated his message from yesterday that this long weekend was a good "rehearsal" for the summer break where we could get into good habits to keep New Zealanders safe.

Bloomfield said we'd been successful to date because of the high-trust model and he was confident that if people saw the benefits of their behaviour there would be good uptake

Hipkins said port workers were being tested fortnightly not weekly because of the risk assessment - though that was being continuously reviewed.

One hundred and fifty international PhD students have been approved for border exemptions.

Community testing over Labour Weekend

Hipkins said it was "imperative" that people with symptoms get a test quickly - Auckland will have seven community centres open over the long weekend.

Bloomfield thanked New Zealanders - especially Aucklanders - "for doing the right thing" as it would help their families and communities stay safe.

Hipkins also thanked the team of five million for playing their part - but said there was no room for complacency and New Zealanders needed to be constantly on alert no matter the alert levels.

Hipkins said the fact we were managing the latest cases within alert level 1 was reassuring and they were a reminder the pandemic was rampant.

Ahead of the long weekend, Hipkins asked that anyone who's sick to stay home, call Healthline and get a test.

He also asked people to use the Covid Tracer app and to wear a face covering in places where you can't physically distance, like on public transport or planes.

Anyone with the Covid Tracer app will get a notification this afternoon reminding them to use the app, he said.

He reminded businesses QR codes should be displayed prominently.

"We know how to prevent the spread of Covid 19 in New Zealand, we've done it many many times."