Jacinda Ardern and Helen Clark on confidence and the future for women

A conversation between Prime Minister Jacinda Ardern and former Prime Minister Helen Clark has been captured on camera for the first time.

The UN Women National Committee for Aotearoa brought the two women leaders together for a conversation to celebrate 125 years of women's suffrage.

Both women shared concerns about the self-doubt that young women have to overcome.

"Men are much more likely to put themselves forward when they're not fully qualified, whereas women want to be 120 percent qualified - and that's the barrier we've got to get over," Ms Clark said.

Ms Ardern agreed, recalling a story Ms Clark shared about when she was first approached to lead the United Nations Development Programme (UNDP).

"Your first response was, 'Oh I'm not sure about that, I haven't got that experience in aid and development' and their reply was, 'Helen you've been the Prime Minister'."

Ms Clark went on to serve as UNDP Administrator from 2009 to 2017, the third highest-ranking job at the United Nations behind the Secretary-General and Deputy Secretary-General.

"It makes the point that we do want to know that we can do it, and maybe we just don't need to have that level of self-assurance," Ms Clark said.

Ms Ardern discussed the particular type of behaviour that can be expected of MPs, especially opposition MPs, that she did not fit.

"There was this notion that unless you had claimed scalps in Parliament, unless you were assertive and aggressive, then you weren't an effective politician," she said.

She asked Ms Clark what she thought the next step was for women's rights, and she said it was tackling the shocking rates of sexual and gender-based violence.

"If a woman cannot be safe in her home, if she cannot be safe in her community, this is an incredible blight on her developing her full potential," Ms Clark said.

"You'll never have gender equality while these levels of violence persist, it is a serious problem in New Zealand and I think for women, we have to beat it."

They talked about the lack of political representation and high rates of domestic and sexual violence in the Pacific. The Solomon Islands has one woman MP, while Papua New Guinea has no women MPs, Ms Clark said.

"I just won't settle for the argument that women are important behind the scenes, I want to see them important at the top table not just behind the scenes."

Ms Ardern said on a political trip through the Pacific she asked "at each stop" why there wasn't greater representation of women.

"Some of the statements I collected from varying men in positions of power were things like 'Well, the women argue too much'. I thought there was a deep irony to that, and that they weren't seeking office.

"I really challenged that, if you're not supported of course it does make it that much more difficult," she said.

She thanked Ms Clark for laying the foundations and allowing her to follow in her footsteps.

"I haven't had this opportunity until now to say thank you. Because of you... gender never came into it for me."

Watch the video for the full conversation.