North Korea's sabre-rattling cut a bit closer to home in the weekend when the rogue state threatened Australia with a nuclear strike.

So does New Zealand have anything to fear from North Korea's nuclear ambitions and threats of war?

Experts say New Zealand, 10,200 kilometres from North Korea, is well-placed to avoid any nuclear fallout from a strike in the Korean Peninsula.

But any military action in the region would likely be felt by New Zealand other ways, not in the least because it plays an ever-increasing role in this country's trade.

It would also place the Government in a difficult position over whether it played any role in the conflict.

How safe is New Zealand?

In short, New Zealand is probably the safest country on earth in the event of a nuclear strike in the Korean Peninsula.

"Really, New Zealand is the place to be if there is going to be a small nuclear exchange," University of Auckland physicist David Krofcheck says.

He defined "small nuclear exchange" as one or two smaller warheads fired by either side.

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The South Pacific is shielded from nuclear fallout in the Northern Hemisphere by global weather patterns.

Prevailing winds and ocean currents around the equator push any radioactive particles eastwards. For this reason, the Fukushima nuclear disaster in 2010 was not considered a threat to New Zealand.

Any particles which were carried in the ocean were slow-moving and heavily diluted.

"We would only be in danger if there was one of the traditional cold war nuclear scenarios with the US and Russia exchanging 1000 warheads each," Krofcheck said.

"For a small exchange, Hiroshima-sized or bigger, we would still not really be affected because of the winds blowing different ways at the equator."

It is believed that the longest range missile developed by North Korea so far, the Taepodong-2, could have a range of 6000km, meaning it could possibly reach the United States or northern Australia.

That is if the missile was not intercepted. Some believe a failed North Korean missile test last week was the result of American hacking.

However, the country has not yet been able to fix a nuclear warhead to a long-range missile. Estimates about when the country could reach this milestone range from 12 months to 10 years.

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Defence Minister Gerry Brownlee was relaxed about North Korea's nuclear threat when speaking to TVNZ on Sunday, saying he wasn't "particularly worried ... other than it's a situation that is under constant monitoring."

How else could it affect us?

The main threat from an escalating dispute on the Korean Peninsula is to New Zealand's trade links.

"I've not seen much evidence at all of any impact yet on our trade with the region," former trade negotiator Charles Finny says.

"But from a trade perspective, any hostility in that part of the world, whether it be South China Sea, Taiwan Strait, or the Korean Peninsula is potentially very negative for New Zealand,"

The escalating dispute between North Korea and the United States has already had an effect on New Zealand trade, albeit a minor one.

After the US placed a missile defence system in South Korea, China retaliated by cracking down on South Korean retailers. Tourist numbers to Korea were also reduced. Those changes had a marginal knock-on effect, because New Zealand supplies goods to South Korea's tourism industry, such as hotels, and its department stores.

If the dispute between the US and North Korea escalated into military action, the impact on New Zealand exporters would be profound.

Key shipping or aircraft routes would be blocked or complicated, and that would have an immediate effect on New Zealand exporters.

"China is our biggest trading partner, about equal with Australia," Finny said. "Japan is our third or fourth and Korea is our fifth. And Taiwan is top 10. So potentially very negative if there was something long-term."

"And obviously if there's conflict that's extremely negative in the short-term, and you'd imagine that trade would just stop."

What can we do?

New Zealand, like other countries, has imposed trade sanctions on North Korea.

The sanctions, which have been in place in 2006, have had limited success in convincing North Korea to limit its nuclear programme or missile tests.

US President Donald Trump has urged China to play a greater role in reigning in its neighbour, and has suggested even tougher sanctions such as on oil, effectively creating an economic embargo.

However, international law expert Alexander Gillespie, from Waikato University, said stricter sanctions only worked on leaders who listened to its population when it was hurting.

"Sanctions brought Iran to the negotiating table. But Iran is a pseudo-democracy. North Korea is no chance. [Kim Jong Un] just doesn't give a s*** how much pain is felt by his country."

The other non-military option was the negotiation of a peace treaty, a difficult task given the unpredictability of Pyongyang's leadership and its stubbornness about weapons testing.

Former US President Barack Obama unsuccessfully tried to get North Korea to end its nuclear programme.

Gillespie said the solution could be in convincing the country to at least stop its missile tests and nuclear expansion in exchange for lifting sanctions, and make ending all nuclear testing a long-term goal.

That would require Trump to take a more nuanced, diplomatic approach than his predecessor; something he has shown no sign of doing so far.