Ardern was was drawn into a sexism row, amid questions around whether or not having a baby would affect her chance of becoming prime minister.
Less than a week into her new job, she has already been questioned twice – on seperate occasions – about potential or eventual parenthood.
“I’m not pre-determining any of that, just like most of the women out here who just make their lives work,” she told TV3.
“It is totally unacceptable in 2017 to say that women should have to answer that question in the workplace.
“It is the woman’s decision about when they choose to have children. It should not pre-determine whether or not they get the job.”
Former cricketer-turned-television host Mark Richardson’s heavy questioning of Ardern drew plenty of criticism.
“Quite frankly, whether a woman intends on having children or not is none of their bloody business,” insisted New Zealand human rights commissioner Jackie Blue.
“Oh, and by the way, it’s illegal to ask those questions as they breach the Human Rights Act.”
Pop culture website thespinoff.co.nz commentator, Madeleine Holden, added: “Asking Ardern about her plans to have children implicitly reinforces the sexist notion that a woman’s primary role is motherhood, no matter how accomplished she is in other areas.”
The 37-year-old succeeded the outgoing Andrew Little on Tuesday – and will attempt to prevent prime minister Bill English from winning a fourth term.