Jacinda Ardern was elected as the new leader of New Zealand's Labour opposition on Tuesday in a unanimous vote, following the resignation of former leader Andrew Little.
"A lot of women in New Zealand feel they have to make a choice between having babies and having a career ... is that a choice that you feel you have to make or already made?" host Jesse Mulligan asked Ardern, after admitting some of his colleagues had said he shouldn't raise it.
Ardern said she had no problems with being asked the question. "My position is no different to the woman who works three jobs, or who might be in a position where they're juggling lots of responsibilities," she said.
"You've just got to take every day as it comes and see if you can make the best of the lot you're given."
"I elected to talk about it, it was my choice ... but for other women it is totally unacceptable in 2017 to say a woman should have to answer that question in the workplace," she said forcefully.
"It is a woman's decision about when they choose to have children. It should not predetermine whether they should have a job or be given job opportunities."
A number of New Zealand commentators and social media users condemned questioning a female leader over her plans for children, saying such questions would never be asked of a male politician.
Online news site stuff.co.nz ran an opinion piece entitled, "No, we don't need to know about Jacinda Ardern's baby plans. Ever."
Ardern is not the first female political leader to face questions over her motherhood plans.
Ardern stepped into the role at a difficult time, just under two months from the next general election on September 23. The Labour party has been out of power since 2008.
Ardern is only the second female leader of the Labour party.