Winston Peters is hailing Jacinda Ardern's meeting with US President Donald Trump as "stellar" while Simon Bridges says the Prime Minister "copped out". 

Filling in as Acting Prime Minister while Ardern is in New York, Peters described the PM's meeting with Trump as the "most impressive meeting there has ever been with the United States where this country is concerned". 

He praised Ardern for meeting Trump, US Vice President Mike Pence, Secretary of State Mike Pompeo, and US National Security Advisor Robert O'Brien, "all together in the same room". 

"Since a request was made way back in 1939 by Walter Nash, the then-Minister of Finance, for the United States to have a free trade agreement with New Zealand, the United States is now listening," Peters told Parliament. 

"The President's comments were absolutely and totally positive."

Ardern said she had a wide-ranging discussion with the US President in New York, revealing he was interested in New Zealand's tourism, the gun buyback and the Christchurch mosque attacks.

National leader Simon Bridges was not convinced the Prime Minister's meeting with Trump - on the sidelines of the United Nations General Assembly on Tuesday morning NZ time - had been a success. 

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"When she met with the leader of the free world, she copped out with the person who could make the most difference on climate change in the world," Bridges said. 

He was referring to Ardern not raising climate change issues during her meeting with Trump - despite delivering a keynote speech on it at the UN - and instead focusing on trade. 

Bridges also said he could not understand why the Prime Minister didn't raise the Christchurch Call in her meeting with the US President. 

The US government did not send a representative to Ardern's first Christchurch Call event in Paris earlier this year, issuing just a statement of support for the principles of what it was trying to achieve. 

Bridges said: "The same is true on the Christchurch Call - she hasn't raised that with the President of the United States of America. Without the United States on board, this is a toothless tiger - it doesn't have the teeth."

Despite 31 new countries and two organisations joining up - bringing the total to 48 countries and three international organisations -Bridges said it is "pretty nebulous, feel-good stuff that that won't achieve anything". 

He made similar comments on The AM Show earlier this month. 

Bridges said if he was PM, he would have discussed trade and climate change with Trump, "because the reality is, if we're to make progress on that issue and the Paris Agreement, we need the United States involved in that". 

He said he would have liked to understand Trump's positioning on climate change. 

"If you're the Prime Minister and you say this is our nuclear-free moment, and that no one can afford the luxury of not copping out, why did Jacinda Ardern do just that?"

In Parliament, Peters heaped praise on the Prime Minister for her trip, which started in Japan hosting the Rugby World Cup. There, Ardern held a meeting with Japanese Prime Minister Shinzo Abe. 

Peters said: "The reality is that the Prime Minister on this trip has been first to Japan, the third-biggest economy in the world, the United States, the biggest economy in this world."

But he was interrupted by an Opposition MP in Parliament who mentioned China. The Deputy PM then launched a follow-up on his attack last week over Bridges' recent trip to Beijing. 

"Simon went to China, the most sycophantic, palm-licking trip I've ever seen."

Last week, Peters described Bridges' interview with state-owned Chinese news channel CGTN as "obsequious, subservient grovelling, kowtowing, [and] palm-kissing nonsense". 

Peters insisted Ardern had a "mega-Monday [US time] with the power structure of the United States in New York and with the President of the United States". 

Earlier this year Peters, as Foreign Minister, visited the US capital Washington where he pitched a free trade deal to the US Vice President. 

Peters said Trump's expression of interest in free trade with New Zealand during his meeting with Ardern was the "most positive news this country has had for a long, long time". 

He said it will "enable us to pay for our infrastructure and social welfare policy going into the future".