Jacinda Ardern doesn't think police will be required to enforce self-isolation, but they will be called up if necessary.
New Zealand now requires all visitors, with few exceptions, to go into self-isolation on arrival in the country. The extreme measure's been implemented to stop the coronavirus pandemic getting a foothold in New Zealand, which so far has only six confirmed cases - all of them brought in from overseas.
"For us, this was the next step - a really, active, decisive early decision, going hard, to make sure that we do what they call flattening the curve," Ardern told Q+A on Sunday morning.
'Flattening the curve' is the goal of keeping transmission slow, so health services aren't overwhelmed.
"That puts a real strain on your public health system. We won't be able to stop cases in New Zealand, but we can try and slow them, which is exactly what these decisions are all about."
But there have been questions around how self-isolation would be enforced, which Ardern sought to answer. She told host Jack Tame so far more than 10,500 Kiwis have successfully gone into self-isolation, without any problems.
"We have someone fill in a form, that's essentially like a Customs form, when you arrive [in the country]," she explained.
"That's then handed over at the airport to a nurse who talks you through what you're required to do to self-isolate. We then follow up with you - Healthline will call you. And we're going to step up that enforcement - things like spot checks to ensure people are self-isolating.
"If you don't self-isolate, there are quarantine powers available to us. We can put you in a facility and monitor your movements. Now my view is that most people - in fact, I've seen no cases where they haven't - are following those requirements."
Quarantine would be in a hospital or other medical facility.
"You're in a medical facility so of course it's not like a prison, but we can put people on the door to make sure you don't leave. Now those are powers we haven't' had to use and I don't anticipate having to use - but they do exist."
Health officials are in charge of ensuring people stay in self-isolation, but if someone refuses to comply and has to be placed in quarantine, police will be involved.
Ardern said now the restrictions are in place, the number of people entering the country will fall to just a trickle - that's what happened when the Government put earlier restrictions on travellers from Italy and South Korea.
"People don't travel when they know they need to self-isolate."
In fact, Ardern fears we might have the opposite problem, based on what Kiwis have done so far.
"One of the problems was people weren't coming out. THey were so paranoid about not doing harm to their community, they were staying longer than 14 days."
If you know of anyone who should be in isolation but isn't, Ardern said you could call Healthline on 0800 358 5453.
"If people wish to contact Healthline with any concerns, they can do that. But ultimately, I don't think that's going to be necessary."
Ardern also revealed the Government would be revealing its economic response package on Tuesday.