US warns of North Korean missile impact on NZ

New Zealand's more than 10,000 kilometres away from North Korea's missile tests but the United States says that distance doesn't mean we're immune from the affects of an attack.

"When you hear the North Korean leader's going to drop an H-Bomb in the Pacific, who does that affect?" says US Ambassador Scott Brown.

 "That affects the Pacific Islands.

"That affects New Zealand - our fishing, obviously our air, the environment."

Mr Brown, who was personally appointed by President Donald Trump, says Kiwis are complacent about what North Korean dictator Kim Jong Un is up to especially given New Zealand's history on nuclear weapons being tested in the Pacific and our nuclear-free law.

North Korea has yet to prove it can fit uranium and a nuclear warhead on a missile and Auckland University nuclear physicist Dr David Krofcheck says, until they do, we shouldn't panic.

"We shouldn't worry too much, because it is 10,000km away and they haven't even proved they can launch a missile without a warhead," he says.

A lot closer is US Secretary of State Rex Tillerson, who's has just visited China to discuss North Korea, but President Trump says there's no point.

"I told Rex Tillerson, our wonderful Secretary of State, that he is wasting his time trying to negotiate with Little Rocket Man," he tweeted.

"Save your energy Rex, we'll do what has to be done!

"Being nice to Rocket Man hasn't worked in 25 years, why would it work now? Clinton failed, Bush failed, and Obama failed. I won't fail."

Foreign Minister Gerry Brownlee says he's fully aware of the possible catastrophic affects from any nuclear testing in the Pacific, but unlike President Trump, he says a diplomatic solution is the solution.