New Zealand PM Jacinda Ardern back at work after maternity leave

STEPPING from maternity leave to parliament, New Zealand's prime minister has opened up about motherhood, nappies, being a role model and what will be life in the public eye for her family.

Ardern on Thursday spoke to local media for the first time since leaving hospital with newborn daughter Neve some six weeks ago.

While saying she had never relinquished her sense of responsibility, Ardern described the opportunity to step back and have time with her first child as a "gift" and the fastest weeks of her life.

"All of the things that people said that I would experience: that idea that you suddenly have this new person in your life that you could love so much and that time will go incredibly quickly, but that the nights will seem incredibly long, all of that has been true," she told Radio NZ.

"But in the back of my mind, of course was my return and I was looking forward to being back. But I know that being back will be different ... I'm a mum now."

While Ardern - who turned 38 last week - accepted she would draw attention as the first elected world leader to take maternity leave, she described herself as "very, very lucky" to have the support of partner Clarke Gayford - who will be a full-time dad and travel with Neve and the PM.

"I absolutely accept this layer of interest because it's not our normal yet. But one day it will be. I'm just perhaps amongst some of the first," Ardern told TVNZ.

"Day to day I'm worrying about feeding, sleeping and nappies, and there's this overlay of interest in what is something that is mundane."

She acknowledged her role as prime minister would mean a public life for her family.

"Neve didn't choose my political life," she said.

"So Clarke and I are trying to balance the fact we want to protect her privacy, but at the same time we want to be a family and I do a very public job."

The prime minister will return to the capital with her family on Saturday and step back into parliament next week.

Neve will travel with her for the time being, including to the United Nations in New York in September.

"I might be at the odd press conference with a little bit of spill on me because I'm not going to hide the imperfections of parenting," Ardern told RNZ.