Inspired by truckers' demonstrations in Canada, protesters have blocked several roads around Wellington's 'Beehive' parliament for nine days with trucks, vans and motorcycles, and camped out on the lawns in front of the distinctive building.
"There has been an influx of protesters at Parliament today, including children. However, the crowd had been orderly," Assistant Police Commissioner Richard Chambers told reporters, estimating there were about 450 vehicles blocking the site, Reuters reported.
"This is a very complex situation and we are mindful of the tactics we need to take so that the situation is not escalated," Chambers added.
Police gave protesters an ultimatum on Tuesday to move out or officials would start towing and seizing vehicles.
Chambers said on Wednesday police had made some progress in engaging with protest leaders and about a dozen vehicles had left voluntarily.
The protest started as a stand against COVID-19 vaccine mandates but those demonstrators have been joined by groups calling for an end to pandemic restrictions as well some drawing attention to other social issues like censorship and rights of the ethnic Maori community. At the peak of the protest, thousands of demonstrators were estimated to be involved.
Prime Minister Jacinda Ardern has referred to the demonstrations as an "imported" phenomenon and rejected calls to remove all restrictions at a time New Zealand is experiencing a surge in COVID-19 cases due to the Omicron variant.
New daily cases are at a pandemic peak, with more than 1,100 reported on Wednesday after some restrictions were eased this month.
A country of five million people, New Zealand has some of the lowest COVID-19 case numbers in the world, largely due to tough coronavirus border curbs and social restrictions. It has reported a total of around 22,300 infections, including 53 deaths.
The country's borders are still closed, with tens of thousands of expatriate New Zealanders cut off from families.