Prime Minister Jacinda Ardern says New Zealand has a lot to celebrate on International Women's Day, but there is still work to be done.

Speaking at an event in Parliament this morning, Ardern said the moment when she could say "we've done it", would be when gender does not feature in the minds of young women in New Zealand.

"A time when they're born in New Zealand and they don't think about the fact that they'll earn less. Where they don't consider whether there is a job they could or couldn't do, because of their gender.

"That they won't question whether or not they will be less safe in their home, in their relationships, in their communities and when they walk at night," she said.

Ardern said she had always been an "angsty woman – I angsted about the world from the time I was very young".

She said it was very hard to celebrate when you view the world that way.

"As long as we have a country where women are over-represented in intimate partner violence; as long as we have women over-represented in low-paid work; as long as we have a gender pay gap, I think probably of all us will only celebrate to a certain degree, while we know there is work to be done."

She said there were a lot of ways the Government could help achieve this and listed a number of ways in which new legislation, such as the increase in paid parental leave and the improvement of pay equity legislation, had helped address some of these problems.

But Ardern said things need to go "much, much further than that".

She shared the story of one of her own role models – activist, author, feminist and former New Zealand politician Marilyn Waring.

As part of a social studies project when she was in high school, Ardern had to create a time capsule of someone she thought had made a big impact on history.

"I chose a young woman called Marilyn Waring."

In 1975 when she was 23, Waring became the youngest MP in New Zealand's history.

Ardern's teacher suggested she give Waring a call for the project – she did, but only reached her answering phone and had to leave a message.

A month later, after the project had been handed in, Waring called Ardern back.

"I had this amazing conversation with her. She took the time to talk with me, a 15-year-old nobody from Morrinsville."

Waring told Ardern: "I can tell you're interested in politics – let me give you a piece of advice, don't go in too early."

A number of years later, not long after Ardern was first elected as a Labour MP, she spotted Waring at an event.

She "made a beeline" over to her to chat, and asked if she remembered the phone call all those years ago.

"She said, 'I do remember, and you didn't listen to my advice.'"

Ardern used the story to implore women in New Zealand to not underestimate the impact they have on those around them.