The Prime Minister is assuring people rushing home before lockdown begins on Wednesday night that some exceptions may be made for those struggling to make it in time.
Jacinda Ardern says she has heard concerns from people worried they may not be able to cross between islands on the Interislander in time to arrive home before the country goes to level 4.
The Government announced the new alert level system over the weekend. After starting on level 2 - which suggested COVID-19 was present but contained - Ardern on Monday raised the level to 3, with authorities saying they now believed there was community transmission of the disease.
At 11:59pm on Wednesday the country would go to level 4, Ardern said, meaning all non-essential businesses would have to close and Kiwis would be required to self-isolate.
Level 4 would last for at least four weeks, Ardern said.
But speaking on The AM Show on Tuesday, the Prime Minister said while there was a clear deadline, she understood that in some cases there would need to be exceptions.
"We're wanting to work New Zealand into a state where everyone's basically in a position where they're staying home self-isolating over close-of-play Wednesday, end of Wednesday - so that's what we're working to," Ardern said. "There will be some services that we need to just make sure that we get people back to where they need to be."
One particular concern she had heard was people returning on the Interislander ferry.
"Just an assurance there - we know the deadline that we've set, that's when we ideally want everyone back to where they need to be but we'll work that through individually with the ferries.
"We don't want people stranded."
Once the lockdown is in place, police will be making sure Kiwis are following the new rules, Ardern said.
"They will enforce," she said.
"Because we cannot let groups of individuals who don't want to follow through make it worse for everyone else. That's where we really rely on everyone doing their bit - collective action - and if they don't we will enforce, we must enforce. I want New Zealanders to know that they don't have to play that role - we will do that."
Ultimately police are "there to look after all of us", she said.
"We will have enforcement but keep in mind people are allowed to leave their homes - don't feel like you can't leave your home and get some fresh air, walk around the block."
The Government has assured people that essential services such as supermarkets, pharmacies and petrol stations will stay open regardless of the alert level.
Ardern said although New Zealand was acting early in a bid to stop the spread of COVID-19 before community transmission got out of hand - like in Italy - the situation was not going to be painless.
"It will get worse before it gets better because we have a lag from the time that people have it to the time that they're symptomatic and then if they've passed it on there will be those then that have a lag in coming through," she said.
There are currently 102 confirmed cases of COVID-19 in New Zealand, with two of those presumed to be spread via community transmission.
The country had doubled its ICU capacity, to around 500 beds, in anticipation of a spike in cases, but the best way to ensure the country was prepared to handle the pandemic was to take social distancing seriously, Ardern said.
"Rather than be in a position where your health services are overrun and people are losing their lives and then move into lockdown, move early - that's your best chance of saving lives and it's your best chance of actually being in it for a shorter time as possible."