"The President was genuinely interested in our election, and spoke about the coverage it had received in Washington DC," Ms Ardern said of the five-minute phone call which came three days after a deal with the NZ First Party landed her the post.

"We are likely to meet at APEC where I look forward to carrying on talks around our role in the Asia Pacific region, and our commitment to a strong relationship with the United States.

"The President also asked that I pass on his warm regards to the people of New Zealand."

The APEC summit will be held in Vietnam during November. Leaders of the 21 Asia Pacific member economies meet to discuss issues in the region.

The summit could be tense for mr Trump after one his first acts in office was to withdraw from the Trans-Pacific Partnership (TPP), signed in Auckland last year.

After Trump withdrew from US-led TPP negotiations shortly after taking office, some of the remaining 11 nations in the pact - including New Zealand under former prime minister Bill English - have lobbied to keep it going.

Leaders involved in talks were hoping to sign a new agreement on the sidelines of APEC, which meant a tight timeline for trade officials to gain concessions while working to hold ground in other areas.

Mr Trump has repeatedly expressed his opposition to free-trade deals, and was also set to sign an order to renegotiate the North American Free Trade Agreement (Nafta) deal between the US, Canada and Mexico.

Even though Ms Ardern has worried some investors with policies such as pledging to reform the central bank, cut immigration and boost spending on welfare, she insists that her Labour Party believes in the benefits of free trade.

"We have signed significant free-trade agreements; we'll continue to do so in the future," Ms Ardern told Sky News.

She said in a separate interview that Labour wouldn't cut immigration by as much as that demanded by NZ First leader Winston Peters, her coalition partner and kingmaker.

Mr Peters, whose populist appeal has seen him compared to Mr Trump, campaigned in last month's election campaign to slash immigration to just 10,000 a year from about 73,000. Labour also wants a cut but only by as much as 30,000.

"Labour's policy remains absolutely unchanged as a result of these negotiations" with Mr Peters, Ms Ardern said.

Separately, Ms Ardern hoped the Turnbull government wouldn't go ahead and restrict Kiwis from university courses in Australia as she may be forced to end a reciprocal arrangement.

Ms Ardern told Sky News on Sunday she hoped the mutual access would continue.

"But if we do find New Zealanders aren't able to access tertiary education the same way as Australians currently do, there will be flow-on effects here," she said.

Stuff.co.nz, Bloomberg, AAP