New Zealand's COVID-19 outbreak lessened again on Thursday with 13 new cases, down from 15 on Wednesday and 21 on Tuesday.

All of the recent cases have been found in Auckland, which remains in a harsh lockdown.

Prime Minister Jacinda Ardern described the case numbers as "solid progress" as New Zealand attempts to eliminate its Delta outbreak.

In the three weeks since COVID-19 returned to the community on August 17, 868 Kiwis have caught the virus.

In that same time, New Zealanders have streamed to vaccination clinics in record numbers.

More than 30 per cent of the entire country have received a dose of Pfizer vaccine in that time, putting pressure on the rollout.

Without an additional source of vaccine, Ms Ardern's government would have needed to slow demand, therefore missing a golden opportunity to up vaccination rates.

Thankfully for Ms Ardern, Spain has answered the call.

"Last night we completed the final details with Spain which will see New Zealand receive over a quarter of a million doses of the Pfizer vaccine," she said.

"Those quarter of a million doses departed Madrid at 1am New Zealand time and are due to arrive in Auckland tomorrow morning.

"I can tell you they are on track because I have following the shipment's movements on Flight Tracker."

The deal is not a swap: Ms Ardern's government is purchasing the vaccine outright from Pedro Sanchez's government.

Ms Ardern is a fan of Mr Sanchez, last year nominating him as one of her most admired world leaders.

She admitted personal contact with the 49-year-old to help the deal's passage but said it was not necessarily determinative.

"It just so happened that there were relationships there that meant I could have those conversations and did so," she said.

Ms Ardern has foreshadowed a second deal this month.

Australia has also made deals to import additional vaccine in recent days, with both Singapore and the UK.

In further good news, there is also a fall in hospitalisations, with 31 Kiwis currently requiring hospital level care, including five in intensive care and three on ventilators.

The total number of hospitalisations during this outbreak is 88, with new data released by the Ministry of Health underscoring the importance in vaccination to avoid serious harm.

Of the 88 hospitalised, just one was fully vaccinated - and that person had not received the full benefit from their jab as their vaccination had occurred in the two weeks prior to catching COVID-19.

More than 80 per cent of those hospitalised were unvaccinated.

As NSW firms up a vaccination target and strategy to end its long-running lockdown, Ms Ardern said she would resist calls for New Zealand to do similarly before shifting away from its elimination strategy.

Instead, she said her target was "everyone".

"I hate the idea of even one preventable death," she said.

"If everyone can be vaccinated is vaccinated, you are potentially saving the life of someone who can't be."

Ms Ardern said 121 cases in the current outbreak had not yet had their 10th birthday.

"These are children who at this stage cannot be vaccinated. So they need us to be," she said.