North Korea's threat to launch ballistic missiles around the US territory of Guam has terrified residents of the small Micronesian island.

But according to US president Donald Trump, the threat of nuclear armageddon will be good for local tourism. 

"Tourism, I can tell you this — tourism, you're going to go up like tenfold with the expenditure of no money so I congratulate you," Mr Trump is heard saying in a video posted to Facebook by Guam's governor Eddie Baza Calvo.

"We are with you 1,000 per cent, you are safe," he added.

READ: North Korea gives details of its Guam missile plans

The governor of Guam appeared to agree with the president, telling him "we've got 95 per cent occupancy and after all this stuff comes down we're going to have 110 per cent occupancy."

Mr Trump and Mr Calvo were speaking over the phone. 

"You've become extremely famous. All over the world they are talking about Guam, and they are talking about you," Mr Trump said. 

Guam would benefit from the exposure, Mr Trump said. Photo: Shutterstock

The US president told Mr Calvo that Guam - which has a population of 160,000 and is about twice the size of Malta - seemed beautiful, telling the governor he had seen images in news reports about the North Korean threat.

"You know, they're showing so much, it's such a big story in the news and it just looks like a beautiful place," he said.

North Korea has said it plans to fire missiles around 40km away from Guam's shore, adding that it expects them to reach the island within 17 minutes of launch. 

Skyrocketing tourism? Photo: Shutterstock

Mr Trump has responded to the plans with some tough talk, saying the US military is "locked and loaded" and that the country will respond with "fire and fury" if provoked. 

Nuclear guidelines

Although Mr Trump has reassured Guam residents that they are safe, the government there has opted to play it safe and issued a fact sheet with advice of what to do in case of a nuclear attack. 

The sheet urges people to take cover as quickly as possible, "under concrete structures or below ground if possible." 

"Fallout radiation loses its intensity fairly rapidly. In time you will be able to leave a fallout shelter," the sheet notes, adding that people should "not look at the flash or fireball — it can blind you."