Prime Minister Jacinda Ardern and Director-General of Health Ashley Bloomfield are set to announce Cabinet decisions about alert levels for New Zealand, except Auckland which remains at level 4.

Bloomfield says essential workers crossing alert level boundaries will be required to undergo weekly testing.

Those people will be expected to have had a test in the last seven days and must show proof of it, he says.

Three thousand people are crossing the border between Auckland and the rest of the country each day.

Cabinet has been meeting this afternoon. Most of New Zealand moved from level 4 to level 3 last Tuesday, 31 August, with Northland following on Thursday night after additional testing, and Auckland remaining at level 4.

Ardern signalled Cabinet would today decide on whether alert levels would change although Auckland was set to remain at level 4 until at least 14 September.

Only five of the 20 new cases reported today were infectious while in the community, and all new cases were in Auckland.

No cases linked to the current outbreak have so far been detected outside Auckland or Wellington, with the last case in the capital reported on Friday.

Public health experts have however warned that if the country does move to level 2, it would be with tighter restrictions than previously such as mask wearing and record keeping requirements.