Prime Minister Jacinda Ardern says every booster that a New Zealander receives will help reduce the spread of Omicron.
Ardern visited a Lower Hutt vaccination centre to mark 90 percent of Māori in the region being double vaccinated.
In a stand-up at the centre, she said having four million New Zealanders vaccinated now is a fantastic milestone.
Ardern said New Zealand is now at 90 percent double vaccinated in every age group except under-12s.
"The booster is incredibly important in the response to Omicron," she said.
Ardern said there has been a range of modelling, but the government has done scenario planning for numbers of 1000 a day to 50,000 a day.
She said the government has been aware that there are groups who had their second dose later in the rollout, but the decision to make the interval between second and third dose is one made by the health experts.
She reiterated that the best approach for New Zealand is getting boosters up. Some people may still experience more severe illness with Omicron.
"It may be milder, but the case numbers ... will be larger."
She said every booster that a New Zealander received would help reduce the spread of Omicron.
Ardern said there's no reason to think New Zealand would necessarily be an exception to the rapid spread of Omicron we've seen overseas, unless we do everything we can.
One of the main changes under the phased plan includes an increased focus on providing care for people at home. Ardern said the government "absolutely" will be working with Māori and Māori providers to work together on supporting this.
Ardern said what's important to note is that it's likely Omicron would not be the last variant New Zealanders dealt with.
She said the rapid antigen tests held by the Ministry of Health were those it has ordered. The government has "absolutely not" taken tests from businesses which were already in the country, she said.
New Zealanders being able to go to a pharmacy to buy a RAT depended on how quickly Omicron spreads, she said.
"We want to make sure that every New Zealander who needs a test can access one, for free."
Government departments are working with industries including food production, and transport logistics.
She said it's really important that people were aware of any symptoms and got tested immediately if they had them.
"The last thing we want are individuals in hospital asking to get a booster, but by then it's too late."
"There's still almost 40 percent who are eligible today but still haven't got one, so I implore you, please get a booster."
Ardern said paediatricians have strongly advised the government to keep schools open in the face of Omicron.
Education Minister Chris Hipkins said when doing things like rolling out new curriculum content, the government wants to be sure that is done properly and carefully, "that it's well prepared and that it's done really well".
There will be plenty of opportunities to celebrate New Zealand history, he said, but bringing that curriculum change in would be a huge burden when schools are also focused on Covid-19.
Tamaiti Whāngai is a kaupapa Māori vaccination centre in the Lower Hutt suburb of Waiwhetū.
Ardern is there to mark the milestone of 90 percent double vaccination for Māori for the Hutt Valley DHB.
New modelling from an overseas health research organisation shows New Zealand could be facing 50,000 daily Omicron infections by Waitangi weekend, peaking at about 80,000 each day just a few weeks later.
Yesterday, a Covid-19 Māori health analyst said more than 106,000 vaccinated Māori are not eligible for a booster shot until after 1 March - too late to protect against the expected Omicron surge.
Doctors are warning they will not be able to help all of their patients when there are thousands of daily Omicron infections.