The Cabinet meets again today and wants to ensure that supermarket supply chains, pricing, and customer and staff welfare are all up to scratch, given their importance to New Zealanders during the lockdown.
"We don't obviously have legal footing to enforce specials, but we can on price gouging," Ardern told Newstalk ZB's Mike Hosking today.
She added that the Government had seen no evidence of that so far.
She had been speaking to Consumer Affairs Minister Kris Faafoi who had checked directly on claims of price gouging of items such as cauliflowers.
While there had been issues of chickens being mistakenly weighted - and therefore mistakenly priced - and some supply issues, the Government had not found any price-gouging issues.
Ardern indicated she was keen on supermarkets opening on days that they were traditionally not allowed to, such as Good Friday and Easter Sunday, so as to give New Zealanders maximum access to food and essential supplies.
But she also wanted to check with supermarkets on whether they needed those days to help re-stock shelves. She said she would have more to say on supermarkets today.
Ardern told Hosking the Government had resolved the issue of mixed messages over where people could and couldn't go in lockdown.
"I think the message around staying local has been clear... but no one has locked down New Zealand before. This is something we did in a 48-hour period. It wasn't always going to be perfect."
The Government was looking at the supply of products such as halal meat - and this was being resolved. The Government and MBIE had taken the approach of being as tight as possible on what represented essential services, and worked back from there.
Ardern and Director-General of Health Ashley Bloomfield spoke about the chances of New Zealand coming down to level 3 in four weeks.
Bloomfield told Hosking that might be possible if modelling showed the level 4 precautions were having a positive impact on the trend line of cases, and if, for example, New Zealand was returning to isolated cases.
Officials believe it will take around 10 days before we see any impact or trend from the lockdown rules, and whether they are working.
Ardern said it wasn't just the sheer number - but the type of cases. For example, if we got to the point of having 100 per cent of cases originating from overseas cases, that was "under control somewhat" compared with other scenarios.
"We are still doing contact tracing on every case, even now."
Hospitals are now just half full, having cleared the decks of elective surgery and outpatient work to cope with a possible onslaught from Covid-19 which has caused the first death in New Zealand.
Anne Guenole of Kaiata, a small settlement inland from Greymouth, died in Grey Base Hospital on Sunday morning after having been confirmed as having the virus on Friday.
Guenole, aged in her 70s, had originally been diagnosed with influenza and officials are still trying to confirm how she might have contracted Covid-19. The case has left family baffled as they mourn her death.
According to a death notice, Guenole's husband Peter died in Christchurch Hospital "with family by his side" in August.
Twenty-one Grey Base Hospital staff are in self-isolation because they did not initially use a visor or eye goggles - part of personal protective equipment (PPE) required for treating Covid-19 patients - when they tended to Guenole.
Meanwhile, supermarkets will today be a focus for the Cabinet, which wants to ensure that supply chains, pricing, and customer and staff welfare are all up to scratch.
The developments come as confirmed coronavirus deaths in the US doubled in two days, passing 2000 yesterday. More than 100,000 people have contracted the disease in the US and 664,000 cases of Covid-19 have now been confirmed across the world, with 177 countries affected.
LISTEN LIVE TO NEWSTALK ZB'S CORONAVIRUS COVERAGE 7.05am: Jacinda Ardern; 7.35am: Ashley Bloomfield; 7.50am Chris Quin
In New Zealand, the number of confirmed cases rose by 63 yesterday, taking the total to 514.
Although the number of new cases was lower than the previous two days, Ardern said the country needed to remain vigilant.
The issues likely to be discussed include whether supply chains are being maintained, whether vulnerable customers are being catered for, and whether price-gouging is anything more than an isolated instance.
Ardern said Commerce Minister Kris Faafoi had immediately followed up on hearing of instances of price gouging on chicken, broccoli and cauliflower.
Most ministers will join Ardern remotely including Deputy Prime Minister and New Zealand First leader Winston Peters from Whananaki in Northland.
Ardern cautioned to read nothing into the fact that after a steep build-up to 85 new cases on Friday, it was followed by smaller numbers on Saturday, 83, and on Sunday, 63.
"None of us is willing to draw any conclusions at this stage," she said.
"We all need to be vigilant. No one can be complacent."
The highest number of cases is in Auckland, Waikato, Wellington and Dunedin.
Of the 514, 177 (34.4 per cent) are within the three Auckland region DHB areas, 70 (13.6 per cent) are in the Southern DHB area, 63 (12.25 per cent) Waikato, and 62 (12 per cent) in the Wellington area DHBs.
Bloomfield said 56 people had recovered from Covid-19 and nine people were in hospital: three in Wellington Regional Hospital; one in Blenheim; one in Nelson; one in Whangarei; and one each in Waikato, Taranaki and Dunedin hospitals.
The Ministry of Health has also started providing an ethnic breakdown of the Covid-19 cases: 74.3 per cent are European; 7.3 per cent are Asian; 4 per cent are Maori; 2.9 per cent are Middle Eastern, Latin American or African; and 2.3 per cent are Pasifika.
Following the West Coast death, 21 hospital staff are in self-isolation because they did not initially use a visor or eye goggles, which is part of personal protective equipment (PPE) required for treating Covid-19 patents.
As is the current policy, they won't be automatically tested – only if they show symptoms. The Public Service Association says members who are home support workers may refuse to work in unsafe environments if they are not provided with PPE.
"We have been flooded with messages from the staff," said national secretary Kerry Davies. "They want to keep New Zealand safe but they're scared they'll get exposed doing so, or put at risk those they are supporting."
Asked at a press conference about care workers specifically, Bloomfield said that in most situations, healthcare workers in a healthcare setting or home and community support workers did not need to use face-masks.
"We have this under constant review … It's the best advice we have at the moment … and we'll update the advice if there's any additional or new emerging evidence."
Ardern was questioned about childbirth in hospital and whether they would allow a support person to remain with the mother after the birth – hospitals are issuing their own separate guidelines.
"You can imagine it wasn't long ago that I was in that same position," said Ardern, who gave birth in 2018.
"But I also recognise the need to keep Mum and baby safe too and that's what hospitals have to juggle at this incredibly difficult time …
"It's the coming and going that presents significant risk. And I have such empathy."
Ardern was questioned about why community newspapers were not regarded as an essential service and she said the concern was around the distribution network and in printing but Faafoi was looking into it.
"If they [community newspapers] can satisfy all of those tests then there might be some opportunity there."
Meanwhile, Ardern announced that the Police had set a new website for people to dob in others suspected of flouting the self-isolation rules, rather than telephone the police and tying up resources. The website is 105.police.govt.nz