Kids quiz Jacinda Ardern on 1080, petrol prices, mental health at PM's Picnic

The Prime Minister faced a tough set of questions on Thursday afternoon as she met with school kids from across Welllington.

Jacinda Ardern heard from many children, all wanting to let her know what they think would make lives better for children in New Zealand.

She said she thought it was important to hear the voices of young people while she reaches towards her goal of making "New Zealand the best place in the entire world to be a child".

Ms Ardern said she's noticed "that the feedback that comes through is that young people and children are thinking about the big issues" - and that was certainly echoed in the discussions she had at her picnic.

"To me, mental health care is important - it can prevent depression, self-harm, and suicide," one child wrote on a card Ms Ardern read aloud.

Mental health was a recurring topic of discussion from the children, with Ms Ardern asking what they though made kids anxious these days.

"There's an image of the perfect child, and it makes kids scared to be themselves," replied one.

They agreed that support from family, friends and school were the keys to working through this problem.

It was a mixed bag of answers when Ms Ardern asked the group what they'd do if they were Prime Minister for a day though.

"I'd buy heaps of motorbikes," said one boy. Another said they'd go to McDonald's, while another announced they'd lower the price of petrol.

But answers like "get more learning support for children in school" and "change domestic violence" seemed to strike a chord with the Prime Minister.

Children's Commissioner Judge Andrew Becroft told media later that while 30 years ago, children may not have been taken so seriously, "there's been a terrific progress made in valuing the voices of children" from a political standpoint.

Ms Ardern wrapped up her chat with some selfies, but not before one child asked if she thought "should we ban 1080?"

"Maybe we'll leave that one for when we've finished," the Prime Minister laughed.