There is "still a long way to go" before New Zealand can move down to Alert Level 1, Director General of Health Dr Ashley Bloomfield said today.
It comes as the Prime Minister is due to release more details about the Alert Level tomorrow.
Jacinda Ardern said Alert Level 1 will still have border controls in place and she continues to "ask people to be mindful of public health".
"What we need to make sure is that we move steadily and cautiously," Ms Ardern said from Rotorua.
"We don’t want to lose any gains and we also don’t want to move prematurely."
New Zealand moved from Alert Level 3 to 2 last week. Currently, the risk assessment for Alert Level 1 is that Covid-19 would be considered to be contained in New Zealand but uncontrolled overseas, with isolated transmission possibly happening in New Zealand households.
Subject to changes, Alert Level 1 does not require physical distancing and there are no restrictions on personal movement, gatherings or on public venues. There would still be rules in place for workplaces and education facilities.
Dr Bloomfield today told media today that New Zealand still has a long way to go before it reaches that point.
"I’m not so worried about the number, I’m worried about us identifying cases, I’m concerned about identifying cases quickly and having really good contact tracing and ensuring we don’t get that community spread again.
"Even if at this point in time we have zero or no cases we can identify, that doesn’t mean we’re out of the woods.
"Elimination is a sustained game."
Dr Bloomfield said if "we relaxed the border in the first instance with Australia, that would be the most likely way for cases to be introduced to New Zealand".
Earlier this month, New Zealand and Australia pledged to introduce a trans-Tasman Covid-safe travel zone which would cut out the 14-day quarantine period as soon as it was safe to do so.
Paul Bloxham, chief economist at HSBC Australia, last night said the possible bubble could be "a really big economic story for New Zealand".
"The Aussie tourists may very well save the New Zealand tourism industry in a pretty big way if that's able to get going."
When asked about it today, Ms Ardern said it "comes down to both sides of the Tasman being ready".
"New Zealand has to be sure it feels confident that we won’t be opening up any risk for Australians, and equally I know Australia wants to do the same for us.
"First step is the domestic tourism, second is the trans-Tasman bubble and we’re all working in earnest towards both."
Dr Bloomfield said by introducing the opportunity for people to travel back into New Zealand, it increased the risk of importing Covid-19.
"What our job is, is to maintain that really strong approach around keep it out, stamp it out."