Coronavirus: Prime Minister Jacinda Ardern urges Kiwis in their 20s to take COVID-19 seriously

Prime Minister Jacinda Ardern has unloaded on Kiwis in their 20s, warning that everyone must take COVID-19 seriously.

She pointed the finger during Wednesday's press conference, saying those in the 20- to 29-year-old age range are the ones identified as having the virus in New Zealand.

"They may think therefore that it won't affect them as much - that they'll be mild-to-moderate," she told reporters.

But the Prime Minister said that particular age range was "the vector for our transmission".

"They're the ones who pass it on," Ardern said. "I need everyone to take this seriously."

During the press conference, she also shed some light on the potential process of moving from COVID-19 alert level 4 to 3.

"We're talking about a short period of time during which we're going to have to build some confidence that we've got the virus back under control and that we have the ability from there to aggressively stamp out cases where we see them," she said.

The lockdown has nearly been in place a week and will likely last another three.

Earlier on Wednesday, the Ministry of Health confirmed a further 47 confirmed and 14 probable cases, taking the country's total to 708.