New Zealand might run out of vaccine supply by next week as the country has only 30,000 doses of vaccine left.

New Zealand Prime Minister Jacinda Ardern said on Tuesday that she can not guarantee that the country will have any doses of COVID vaccines left by next Tuesday.

New Zealand solely relies on Pfizer for its vaccine rollout as available doses for distribution drop below 30,000.

"We've planned based on what we're due to receive from Pfizer. If we receive what we anticipate when we anticipate it, then we've got a plan," Ardern to the reporters.

"If there's any slip in the timeline of those deliveries, they will be an effect ... things will be very tight," she said.

New Zealand, which has been largely successful in keeping the virus out through a border regulation, has scheduled mass vaccination for the last six months of the year.

The News Zealand government has delayed delivery as it builds capacity in its embattled health system for the mammoth undertaking and has signed deals with Pfizer to vaccinate every consenting Kiwi this year - a pledge it is holding firm to.

As of last week, it has administered 1.019 million doses of the Pfizer vaccine, with 13 percent of Kiwis receiving at least one shot.