Prime Minister Jacinda Ardern has sent in a military leader to review and oversee border quarantining following the bungle which saw two women granted compassionate leave without taking Covid-19 tests.

The two women later both tested positive for Covid-19, but not before driving from Auckland to Wellington.

Ardern said the bungle was completely unacceptable and the "rigour" of the military was needed to sort out what was going at the border.

Currently only Kiwis are allowed to come to New Zealand, other than a small group of exceptions. Those Kiwis are required to stay in mandatory isolation within a hotel for two weeks, or a more strict quarantine if they are symptomatic.

Since the move to level 1 tests are supposed to be required at around day 3 and day 12.

The pair left managed isolation on a "compassionated exemption" after the sudden death of a parent in Wellington.

Ardern has now suspended all compassionate exemptions.

"I know the decision to suspend compassionate leave will not be a popular one, but it is the right one," Ardern said.

"My job is to keep New Zealanders safe."

She appointed assistant chief of defence Air Commodore Darryn Webb to review and oversee border management from here on out.

"We need the rigour, we need the confidence, and we need the discipline that the military can provide," Ardern said.

He would be able to use the military to make sure the border was being properly handled.

"It is totally unacceptable that procedures we were advised were in place were not. Our job is to fix that."

"There is no room for error."

Deputy Prime Minister Winston Peters said he had been calling for the military to be involved since day one and was pleased it was finally happening.

National leader Todd Muller said the health minister David Clark should be sacked over the matter.

"What does it take for this Prime Minister to acknowledge incompetence and actually sack a Minister?" Muller said.

"The economic impact is enormous, and the country looks to the Government to say, "Have you got your borders under control?", and the answer is no. It is shambolic, it is hopeless."

Ardern rejected this call, saying she and Clark were basically in the same position of being failed by those on the ground.

"He is part of fixing this issue, not part of the problem."

Peters agreed, saying a minister can't always be responsible for operational failures.