Prime Minister Jacinda Ardern has struck out at US President Donald Trump's "s...hole" comment as "hugely offensive".

Ardern stopped short of calling the quote racist when asked about them on The AM Show on Monday morning.

Trump has been reported to have said "Why are we having all these people from s...hole countries come here?" at a meeting with lawmakers.

He has now denied making the comments but many who were in the meeting stand by their accounts.

"There's no other way to describe a response to that, other than hugely offensive," Ardern told The AM Show.

"That statement is offensive. How could you describe it in any other way?"

"It's not just about the country - it's a remark about the people of that country. 'Why are we letting those people in?' is his general remark there."

When pushed on whether she saw the comments as racist, Ardern demurred.

"Some have described it that way. I know the African nations in particular have described it in that way... There's no doubt those are offensive remarks," Ardern told The AM Show.

"You can certainly take pride in your nation, as New Zealanders do. We're enormously proud of the country we are. But we don't do that in such a way that that diminishes the value of another country."

She made clear however that such comments would not get in the way of the US/NZ relationship, as "America always goes beyond one person".

Before taking over the leadership of the Labour Party Ardern participated in the Auckland Women's March in response to Trump's inauguration.

After her election she did declined to clearly articulate her views on the controversial president, saying she believed Kiwis knew how she felt.

The pair have spoken on the phone and briefly met at the Apec meeting in November.

There was speculation that Trump mistook Ardern for Canadian Prime Minister Justin Trudeau's wife, something she later denied.

She told Newsroom that Trump lightheartedly mentioned her election had "caused a lot of upset in her country".

She responded - also in a joking manner - "no-one marched when I was elected."