Wellington: New Zealand Prime Minister Jacinda Ardern declared on Monday (October 5) that the country "beat the virus again" and announced restrictions in the largest city would be eased, after a second Covid-19 wave was contained.

New Zealanders enjoyed 102 days without community transmission as the virus was believed to have been eradicated in late May after a strict national lockdown.

But a new cluster emerged in Auckland in August, forcing the city of 1.5 million into lockdown for almost three weeks.

PM Ardern said Monday the virus was now under control and congratulated residents for enduring the second lockdown as no new confirmed cases were reported in Auckland for 12 days now,.

"It felt longer and dragged on in what was already starting to feel like a very long year," she said.

"But despite this, Aucklanders and New Zealanders stuck to the plan that has worked twice now, and beat the virus again."

Ardern said from late Wednesday Auckland would join the rest of New Zealand on level one, the lowest rating on the government's four-tier virus alert system.

Under the change, there are no restrictions on social gatherings, allowing the second Bledisloe Cup Test in Auckland on October 18 to be played in front of a full stadium at Eden Park.

"This is positive news that (Auckland fans) will be able to enjoy Test match rugby," New Zealand Rugby said in a statement.

New Zealand has recorded just 25 Covid-19 deaths in a population of five million, with 40 active cases in the country on Monday.

But Ardern, who faces a general election on October 17, warned success could not be taken for granted.

She pointed to a decline in the use of the official Covid-19 tracing app and falling virus test numbers.

"A resurgence of the virus is not our only worry, resurgence of complacency is right up there too," Ardern said.