COVID-19: Jacinda Ardern reveals what it would take for New Zealand to go back to alert level 2

On Monday New Zealanders were overjoyed at the news the country would drop almost all COVID-19 restrictions and move down to alert level 1 at midnight.

It's taken three long months to get there - but we may not be completely out of the woods yet.

Prime Minister Jacinda Ardern warns it is possible New Zealand will need to go back to level 2 if cases continue.

"It's not just about the cases, it's the nature of the cases," she told The Project on Monday evening.

"If we have 10 cases a day but they all come from people who have been returning home and are in quarantine then that's very very different to if we pick that up through community testing."

Even if cases do climb, Ardern says New Zealand is in a better position than most.

"We have strong testing regimes, a contract tracing system - and not every country has that - and a programme of quarantine and isolation so all that will make a difference for us to try and prevent us going back through alert levels," she says.

At alert level 1, physical distancing will be no more, night clubs can reopen, and there are no more limits on gatherings.

The only thing which remains strictly under control is New Zealand's borders - they will stay closed to anyone who is not a New Zealand permanent resident or citizen.

Despite receiving criticism for not relaxing other restrictions sooner, Ardern says she knows she made the right decision.

"We have acted cautiously - we all wanted to open as soon as we could but we also didn't want to jeopardize all of the good work New Zealanders did.

"We're amongst one of the few in the world that has opened back up - so I think we've got it right."

Watch the full interview above.