Cabinet meets today to discuss making masks mandatory on all domestic flights, and all Auckland public transport in a bid to prevent further community transmission of Covid-19.
The new rules could be in force as early as Thursday, though some experts say the public health order should be broadened to give more protection against the deadly virus.
It follows a community infection scare last week after an AUT student tested positive for the virus after going to work and visiting various other business in central Auckland while potentially infectious.
Ardern said today that the request for CBD workers to stay home on Friday took into account the various risks.
She old Newstalk ZB's Mike Hosking that it was necessary for 24 hours of caution to establish the link with the existing cases as it enabled time to get the genome sequencing ahead of taking more drastic action.
"Had that case come back and not been linked with the one we had in the inner city then that would indicate a much bigger problem."
The alternative was to not do anything, cross your fingers and then see unchecked community spread.
"I don't want that," she said.
Cabinet would be discussing the mandatory use of masks today, Ardern confirmed. If adopted, mask use would be required for the "foreseeable future".
"We're thinking about places that it's hard to trace people," she said, referring to buses.
Yesterday a neighbour of the AUT student was confirmed as a positive case following further investigations.
There were also two new cases; both are returnees in managed isolation.
The new case connected to the Defence Force cluster was confirmed after returning a "weak positive" result on Saturday.
The person's initial test was negative but a further test picked up the weak positive result which officials investigated further.
The Ministry of Health said the test results indicated a "very recent infection".
The neighbour was classed as a close contact of the AUT student - also known as Case D - who lives in the Vincent Residences and attended work last week at A-Z Collection on High St despite being unwell.
The neighbour has been in the Auckland quarantine facility since November 12.
The Auckland Regional Public Health Unit has also identified seven close contacts and three casual contacts. All have been contacted and testing arranged. Testing for all 10 contacts was expected to be completed by last night.
There are no places of interest identified to date for this latest case.
The other two cases in managed isolation are returnees from the UK and Dubai. Both have been transferred to the Auckland quarantine facility.
