Social Development Minister Anne Tolley didn't tell a United Nations committee that New Zealand has an official measure of children who are homeless or live in poverty, she says.
Opposition MPs have been calling for a consensus about how to measure poverty.
Mrs Tolley and a delegation of officials were questioned by the UN Convention on the Rights of the Child (UNCRC) in Geneva last weekend as part of its five-yearly report.
She said: "They asked a question about poverty, they asked a question about how many children were homeless and did we have an official measure - of course, we do have an official measure."
Today in Parliament, Labour Party children's spokesperson Jacinda Ardern asked about that comment.
"What official statistics was she referring to, when in her first answer she refused to give a number [for how many children live in homelessness and poverty]."
Mrs Tolley replied that she had been misquoted.
"The answer that I gave at UNCRC was very similar but I did give them MSD's [Ministry of Social Development] current figures."
Ms Ardern asked Mrs Tolley whether the Ministry of Vulnerable Children would focus on those living in poverty.
Mrs Tolley said the role of the ministry was to reduce abuse and neglect of children.
Ms Ardern then asked whether a child living in poverty was vulnerable.
Mrs Tolley said families who did not have a a lot of money did not necessarily abuse their children.
"I find it offensive that the opposition is suggesting that just because you're poor you beat your children."
Ms Ardern said if the ministry only dealt with those who were being abused, then it was just a re-brand of Child Youth and Family.
The minister denied that.
"I have made it very clear this is not a rebrand of Child Youth and Family. We've had that many many times before and children continue to be abused and neglected."
Mrs Tolley said she proposed the name of the ministry to Cabinet, before it was approved.