Health Ministry head Dr Ashley Bloomfield says he is thinking of recommending the use of masks in shops and public transport if New Zealand needs to return to alert level 2 for Covid-19.
Bloomfield told Radio NZ this morning that the ministry was actively looking at scenarios where mass masking may be required.
"We're looking at situations where masks might be deployed and recommended for the general population," he said.
"Our thinking at the moment is that even at alert level 2 we would be encouraging people to use them in confined spaces, so public transport, shops and so on."
But that would be considered voluntary at level 2, he said, and his intuition is that it would be ramped up to mandatory at level 3.
"Because remember you're deploying all these things including the masks to try and avoid going into a lockdown again."
While there was no firm decisions on masks yet, he encouraged people to have some stocked at their homes, in the same way they have an earthquake kit in case of emergencies.
Work was also under way to check how much is available in the private sector and to ensure there was enough for everybody, he said.
The ministry said in a statement at 1pm that it is "actively considering its advice to the public on use of masks, as we look at steps the public could take to be better prepared for a possible further outbreak of Covid-19".
"The updated World Health Organisation advice is that masks are effective in helping to reduce the spread of Covid-19 when worn by the public where there are cases of community transmission.
"The WHO also suggests that people should be prepared for the use of masks before the need to use them arises.
"We know that masks have been successfully used overseas to reduce transmission of Covid-19.
"Masks can be particularly useful when people are in close proximity to each other – including on public transport, in shops, and in other confined spaces.
"If there are further outbreaks of Covid-19, masks will be one important component of our strategy for containing the spread of the virus."
Bloomfield's interview with Radio NZ's Morning Report was one of several interviews he has done today to warn New Zealanders against complacency as our closest neighbours in Australia go back into full lockdown to battle a new Covid outbreak that has killed 125 people in the past three weeks.
He told NewstalkZB host Mike Hosking that the Health Ministry was bracing for a second wave of Covid in New Zealand, where only 22 people died between March 29 and May 24.
"We don't want to end up like Melbourne and there's no room at all for complacency, that's why we've got all our planning and preparation going full steam ahead," Bloomfield said.
"We've got everything in place we think minimises the risk down to as low as possible but there are still hundreds of people still working in the facilities and working at the border.
"So far we have been successful but remember that is where the cases came from in Victoria which has led to this huge outbreak.
"This is a tricky virus and we just have to be very vigilant. Part of that is doing testing in the community to detect any infection that might get through as quickly as possible."
He claimed contract tracing was in good shape with a large-scale test run planned in a couple of weeks' time. Testing capacity was now above 3000 cases a day.
However, Bloomfield said while the health agencies were prepared for the next wave it was down to Kiwis to do their part.
"We need to be fully prepared - and that's everybody, not just the health sector.
"When we last had the outbreak here, some of the people who were being looked after in hospital by people trained in the use of PPE [personal protection equipment], we still saw some breaches of people who were using full PPE. The virus is not straightforward. It's tricky."
He said there were very tight processes in the managed isolation and quarantine facilities to prevent the spread of disease.
He said the ministry was undertaking audits of the facilities to make sure the staff were all using PPE.
"Our infection control is good. So we're doing everything we can but part of keeping New Zealand safe is to do surveillance testing. It's a core part of our programme."
The Government this week relaunched a campaign to raise community awareness of Covid-19, instructing people to "be ready" and take a test when they were given the opportunity.