Omicron is likely to enter the community in Auckland in the next two to three weeks, according to top officials.
Covid vaccination programme clinical director Dr Anthony Jordan cited modeller Michael Plank and epidemiologist Michael Baker estimating that the highly transmissible variant could be found in Auckland's community within three weeks.
This estimate is based on the number of Omicron cases that had been found at the border.
"The more people you have at the border [with Omicron], the greater the likelihood a case could slip through," he said.
"I wouldn't second-guess what [Plank and Baker] say but that's the timeline we're dealing with."
Asked on what number of cases would be expected in the first weeks of the outbreak, Jordan said it was difficult to predict.
However, looking at the spread in Australia, Jordan said it appeared cases were doubling every two to three days.
Today there were 28 new community cases of Covid, and 13 at the border, down from 65 yesterday.
The community cases are spread across New Zealand with the largest number of new cases in Auckland, followed by Bay of Plenty, Wairarapa, Canterbury, Lakes and Hutt Valley.
There are 34 people in hospital with Covid-19. Four are in Auckland's North Shore, eight are at Auckland City, 17 are at Middlemore, four in Tauranga and one in Waikato.
Two people are in ICU fighting the virus.
Health providers are now supporting 878 people in the Auckland region who were isolating at home, including 180 people who had tested positive for the virus.
Across the country 95 per cent of eligible people have received their first dose and 92 per cent are fully vaccinated. To date, 637,058 booster doses have been administered.
From January 17 the rollout of the vaccine for children aged 5-11 begins.
A new family-friendly drive-through vaccination centre is opening on Auckland's North Shore on Monday to help cater for demand, at the Eventfinda Stadium in Wairau Valley.