A single COVID-19 case in New Zealand has sparked another full national lockdown. 'We need to again go hard and early,' the Prime Minister said.

• New Zealand has gone back into lockdown after a single suspected Delta case in the community.
• A 58 year-old-man tested positive for COVID-19 with no immediate evidence that he'd traveled abroad.
• PM Jacinda Arden said New Zealand needed to go "hard and early" to stop the Delta variant spreading.

New Zealand is back in strict national lockdown after one 58 year-old-man tested positive for COVID-19, with no immediate evidence that he'd traveled abroad.

Officials assume that the infection was caused by the highly-infectious Delta coronavirus variant.

National statistics suggest that all of New Zealand's cases since February have been detected at its border, rather than in the community. The country, of nearly 5 million people, has recorded just 26 COVID-19 deaths since the start of the pandemic, and has favored strict lockdowns.

Prime Minister Jacinda Arden said in a briefing on Tuesday that Delta, which had caused all but one of New Zealand's COVID-19 infections since late June, was a "game changer."

"It means we need to again go hard and early to stop the spread. We have seen what can happen elsewhere if we fail to go on top of it. We only get one chance," she said.

Arden said that the decision was made on the basis it was "better to start high and go down levels" of lockdown.

"We've seen the dire consequences of taking too long to act in other countries," she said.

From midnight on Tuesday, New Zealanders can only leave the house for exercise, supermarket shopping, essential medical care including pharmacy visits, and for getting a test, Arden said. They must wear a mask.

This is New Zealand's second "Level 4" lockdown, the nation's strictest level.

Arden said that it would last three days for most of the country except Auckland, New Zealand's largest city, where the man lived, and the Coromandel, where the man traveled to over the weekend.

Arden also suspended the nation's vaccine rollout, which already lags behind most other countries, for 48 hours, while measures were put in place to continue it safely.

New Zealand has fully-vaccinated 18.6% of its population, according to Johns Hopkins University. The world average is 23.6%.

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Dr. Ashley Broomfield, chief executive of the Ministry of Health, said in a briefing that the man, who was unvaccinated, developed symptoms on Saturday when on a weekend trip to the Coromandel on the east coast of New Zealand's North Island, and was tested by his family doctor in Auckland on Monday.

He was now self-isolating, Broomfield said. The man's wife, who was vaccinated, had tested negative.

Health officials said the man had no obvious travel history or contact with anyone who had traveled. They were trying to establish how he got infected, they said.

The country first went into Level 4 lockdown on March 26, 2020, when it had recorded fewer than 300 cases, and no deaths. The country has recorded 2,927 COVID-19 cases and 26 deaths since the start of the pandemic, according to Johns Hopkins University.

There are currently 43 New Zealanders with COVID-19, and an average of 1.07 daily new confirmed COVID-19 cases per million people, as of Monday, according to Oxford University's Our World in Data's most recent stats. For comparison, on the same date, the US had an average of 394.89 daily new confirmed cases per million and the UK had 418.85 new cases per million.