US President Donald Trump stunned the political world Thursday with an impromptu White House news conference at which he railed against his perceived enemies in the media, calling them "dishonest" and "out of control".

The US leader has repeatedly ignored presidential decorum, including in his relations with loyal allies like Australia, reportedly lambasting Prime Minister Malcolm Turnbull during a phone call last month and later attacking an agreement with Canberra on refugees as a "dumb deal".

At a press conference in New Zealand, Turnbull, who has repeatedly insisted relations with key ally the United States remain strong, was asked about Trump's views of the media.

"Winston Churchill once said that politicans complaining about the newspapers is like a sailor complaining about the sea," Turnbull told reporters in Queenstown.

"There's not much point. It's the media we live with.

"We have to get our message across and we thank you all in the media for your kind attention," Turnbull added with a smile.

Related Turnbull focuses on US refugee deal over NZ offer

The spat flared over an agreement struck in November to resettle in the United States an unspecified number of the 1,600 people detained by Australia on Pacific islands. Many are Iranians.

In Queenstown, Turnbull met his New Zealand counterpart Bill English and agreed to pursue the Trans-Pacific Partnership, despite Trump's decision to dump the massive trade deal that encompasses a dozen nations.

"In light of the intention of the United States not to ratify the TPP, the two Prime Ministers agreed that Australia and New Zealand would work together to engage with other TPP partners on the way forward, over the coming months," a joint statement said.