Ardern is in Hamilton campaigning and at a Grey Power meeting talked about policy, including reinvigorating the regions and boosting police numbers.
She did not delve into Labour's immigration policy which the party estimates would reduce net migration by 20-30,000 a year. That policy was announced by former leader Andrew Little but Ardern has not changed it.
"Our policy has remained the same for the last several months. I have made no change to that policy. Yes, we have infrastructure issues in Auckland and we know we need to address those - we need to build more houses.
"We wouldn't be having this conversation if there had been proper planning upfront by the current Government.
"That's another reason I absolutely refute the statement that was made there. And everyone who I think has been watching this campaign will know that what was said there was absolutely false. And, frankly, offensive."
The Trump comparison was made by a journalist who was reporting from "quite a distance from the campaign", Ardern said.
Ardern spoke to media at Waikato University after addressing a large crowd of more than 800 students, in which she spoke mostly about climate change and the need to clean up New Zealand's waterways.
Her diplomatic protection officers earned their pay after her speech as hundreds stayed for about 30 minutes to get photographs with the Labour leader and have a quick word. She was eventually extracted from the throng for the media stand-up.
Ardern is now heading to Tokoroa to meet workers at the OJI Fibre Solutions Kinleith Mill.
