Labour leader Jacinda Ardern says she takes offence at being compared to Donald Trump by the Wall Street Journal.

The publication made the comparison in a tweet promoting an article about Labour's rise in polling under Ardern's leadership.

"Meet New Zealand's Justin Trudeau - except she's more like Trump on immigration," the tweet said. The actual article did not make the comparison.

Meet New Zealand's Justin Trudeau—except she's more like Trump on immigrationhttps://t.co/HXs3FfmrWe

— Wall Street Journal (@WSJ) September 5, 2017

Asked about the tweet today, Ardern said she proudly stood behind Labour's policy to double the refugee quota.

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.