The prime minister has confirmed that Northland will move to alert level 3 at midnight tonight as planned.
Checkpoints will be set up between Auckland and Northland, and the decision will be reviewed on Monday.
The checkpoints will be at SH1 and Mangawhai Road, Mangawhai Road and north of Cole Hill Road, Black Swamp west of Rakau Road, and Mangawhai Road and Kings Road, and Mangawhai Road and Ryan Road.
Police said they will begin setting up these northern checkpoints from early this evening.
Watch the latest update from the prime minister and director-general of health here:
Prime Minister Jacinda Ardern said 27 extra wastewater samples were taken across Northland on Monday and Tuesday and none have detected Covid-19.
While the case numbers were moving around a little, Ardern said the important thing was that "we are starting to see some positive trends in the numbers".
She said the rolling daily case number average is 61, down from about 77 five days ago. Fewer people are infectious in the community than there had been.
Cases of in-household transmission would continue to be found, she said, but lockdown was necessary for extinguishing those last chains of transmission.
"If you are a contact, if you have been at a location of interest and advised to stay home as a result you absolutely must do so. It is such an important message."
Ardern said of the cases reported today seven were considered infectious in the community and they had nine exposure events among them. Of those, five were visits to a supermarket, two were visits to a health service or pharmacy.
There were 49 new cases of Covid-19 announced in the community today.