Prime Minister Bill English says US Secretary of State Rex Tillerson had reassured him of the US' ongoing engagement in economic and security spheres in the Asia Pacific.
Tillerson and English met at Premier House this morning.
English said they discussed New Zealand's disagreement with the US decision to withdraw from the Paris Agreement and compared notes on China.
Tillerson is in New Zealand for a few hours after visiting Australia, where he also faced questions about America's apparent increasing isolationism and decisions to drop out of the Trans-Pacific Partnership and the Paris agreement on climate change.
Tillerson said he had wanted to reaffirm the strong relationship between the two countries.
He referred to World War II and the US valuing the ongoing defence relationship with New Zealand, which was seen in the deployment to train Iraqi forces in the Middle East today.
"We are very thankful of the contribution made by New Zealand troops.
"That relationship and that shared sacrifice has spanned many conflicts over the years."
Asked how New Zealand could trust the US to continue to show leadership given its increasingly isolationist stance and withdrawal from the TPP and Paris Agreement, Tillerson said he took exception to the Trump Administration being described as "unpredictable' saying President Donald Trump had campaigned on both the TPP and the Paris Accord.
"In both cases, the President clearly took these actions because they were not in the interests of American people and our own prosperity."
He said the US had every intention of remaining engaged in trade relationships on a bilateral basis.
"The US has an extraordinary record of reducing greenhouse gas emissions."
He said the levels in the US were the same as in the 1990s.
"We have every expectation that record will continue. There's no reason it should stop just because we withdrew from the Paris Agreement."
Tillerson said he had spoken to English about handling North Korea, saying the US had called on any country with links to North Korea to put pressure on it to reconsider the path toward nuclear capability.
"We are very serious about making sure they never have weapons or the means to deploy them against the US and they shouldn't deploy them against other countries as well."
He said they also discussed the South China Sea, saying there was a need to convey to China the message that increasing military action in the islands was a threat to stability.
He said contributions by nations towards counter-terrorism was very important, as the tragic events in London over the weekend showed.
He said it illustrated the need to win the battle of ideology on social media as well as on the battlefield.
"Only the Muslim faith can handle this. We want to be supportive, but they have to take this on and I think we are beginning to see signs they are ready to take this on."
The US has asked its partners to increase their contributions in Afghanistan - including an extra two personnel from New Zealand.
Asked about Trump's unpredictability on Twitter, Tillerson said he did not intend to advise Trump on such matters.
"The President has his own unique way of communication with the American people and the world."