For Daniel Bredenkamp, a mechanic who relocated from South Africa in the weeks before the pandemic hit, it would mean seeing his wife and two children for the first time in 16 months.

"I've missed more than a quarter of my daughter's life," he told AAP.

"It's really taking its toll on me. Physically, mentally, spiritually, in any way it can.

"And at this point I don't know whether I'm going to be alone this time next year. It's so hard."

Mr Bredenkamp's story is typical of hundreds of migrants who moved to Aotearoa in the months before March, when COVID-19 prompted border closures.

It's not uncommon for families to move separately due to job opportunities, school terms, or to tidy up loose ends.

Immigration New Zealand paused applications for family reunifications in the wake of COVID-19 and has yet to consider applications since.

"At first we thought the delay might be two or three months," he said.

"They'd look at them in November. November came and they postponed it to March.

"So they're not processing the visas. There's a humanitarian border exemption but keeping children from their parents is not included."

Other exemptions to New Zealand's border regime - which largely restricts overseas arrivals to citizens - have angered separated families.

"Kiwis coming home should be prioritised and we fully agree," Mr Bredenkamp said.

"But they're letting in sports teams. They let in a production of The Lion King. They let in millionaire yachties for the America's Cup. It's so inconsistent."

In 2019, Polina Chernyshova took up a PhD in mechanical engineering at Auckland University of Technology while her Moscow-based fiance, also a mechanical engineer, works at aircraft giant Boeing.

They have been apart since, with Ms Chernyshova unable to leave New Zealand as she wouldn't be let back in, losing her job and studies.

"It's terrible, it's completely terrible. We don't know when we can see the other and we don't know when we will know. It is so unfair," she said.

Mr Bredenkamp and Ms Chernyshova travelled to Wellington to protest outside parliament this week, gathering support from both the right-leaning opposition National party and the left-wing Greens.

Opposition leader Judith Collins said the trans-Tasman bubble - which would clear Australians from the quarantine system, freeing up thousands of places - could solve the problem.

"They're very skilled people who have come into New Zealand on work permits, able to bring their families in who have stayed behind to sort things out," she said.

"With spots opening up in managed isolation, some spots should be made available to these essential workers who have done nothing wrong."

Greens immigration spokesman Ricardo Menendez March accepted a petition from the desperate families, agreeing with Ms Collins.

"It's a devastating situation ... families separated by the pandemic deserve a fair shot at being reunited," he said.

Ms Ardern's government has acknowledged the issue - asking Immigration New Zealand for a solution - but is yet to solve it.

"We accept that a lot of pain has been caused by those border closures, and in some cases we do have a bit of unfairness in the system," Ms Ardern said.

Australian Associated Press