Auckland Mayor Phil Goff says the city won't be put into lockdown until it's absolutely necessary, fearing people won't follow the rules if he moves too quickly.
The country's biggest city has had 20 confirmed cases of COVID-19, out of New Zealand's total of 52 as of Saturday afternoon. One of the Auckland cases hasn't yet been linked to overseas travel, possibly being one of the first cases of community transmission.
Goff told Newshub Nation on Sunday while he'd like to "keep ahead of the curve", he won't make moves "based on random opinion".
"We do it on the basis of expert opinion we're getting from health authorities," he told host Simon Shepherd, saying he's listening to Director-General of Health Ashley Bloomfield and other Government experts.
Auckland Council has already shut facilities like libraries and pools in an attempt to halt the spread of the disease, which has killed 13,000 people overseas.
When it comes to ordering businesses shut and people to stay in their homes, Italy-style, Goff said "timing, I guess, is everything".
"If you're too far ahead of people then you get poor compliance because they're not ready for it, they don't understand the need for it. If you're following too after you should have acted, then you're inviting this situation to get more extreme than it will get."
Photos sent to Newshub showed people ignoring advice to stay away from each other and large gatherings in particular, with dozens of people crowding around bars in Wellington on Saturday night.
The owner of one of the bars told Newshub the queues are due to doing headcounts.
"I had my security staff standing there with a form. People are just going to have fill them out. It means there is a bit of a queue at the door, but we gotta do what we gotta do," he says.
They'll also be required to do headcounts ensuring there are no more than 100 people on-premise - including staff, move tables a metre apart, and move any pokies machines a metre apart too.
Goff said he saw people out late hugging on Ponsonby Rd.
"Those habits are going to have to change. We've got to take this seriously. Because you're young it means you're not liable to be mortally affected by that, but you're still a potential vector and you've got to think about other people you might damage if you don't follow this advice."
If a call is made to shut the city down, Goff said it would be made in conjunction with Government officials. Prime Minister Jacinda Ardern on Saturday unveiled a four-level alert system, which can be applied nationally or regionally.
'You don't want 75 different responses to COVID-19 around the country," said Goff, who said the alert system makes sense.
"The Government takes the lead through the Ministry of Health, they've got their expert panel there, and we will follow closely on their advice and we will feed in information from our end as well."
While no lockdown is imminent, Goff said that could change rapidly.
"We've seen in Italy it's gone from zero to thousands of deaths in the space of less than a month. So we're ready to act very quickly... and keep ahead of the curve so you're carrying people with you, but communicating then why we are making these changes to make sure that people comply.
"We in the Government can show leadership, but if people aren't following then that defeats the purpose. We need people to take responsibility for themselves as well."