People living in Guam may only have 14 minutes between North Korea launching an attack and the weapon reaching the island.
That means locals living on the small island, a US territory, will have even less time to react as news of a launch by Kim Jong-un filters through.
Homeland Security in Guam said on Friday that a public warning system in place that would alert residents of the island of 160,000 people that a missile is incoming.
On the same day, advice on what to do in the event of a nuclear attack, including staying inside and not looking at the fireball, was posted on Homeland Security’s website.
Tensions between North Korea and the US are increasing, with Guam at the centre of the war words between Kim Jong-un and Donald Trump.
It is not known whether the North Korean leader will follow through on his plan to fire four ballistic missiles into waters off the coast of the island, which the country’s military now has the ability to do.
However, many people living in Guam appear to be fairly relaxed about the prospect of nuclear war, instead claiming they are more nervous about a typhoon striking their home.
Rolando Zepeda, a teacher, said he was not making any emergency plans for a nuclear attack.
He added: ‘But I am always quick to shutter up whenever we get typhoon advisories or tsunami warnings.
‘Kim Jung-un is as crazy as typhoons but I am more scared of typhoons because they are real threats.’
Janice Furukawa, who has prepared a typhoon emergency kit, said: ‘To be honest, I’m more worried about the projectiles from the typhoons when we get strong winds than whatever projectiles Kim Jong Un says he will launch on Guam.’
The view was echoed by Guam governor Eddie Calvo who added: ‘You know typhoons can strike anytime, so that means families are making family emergency plans and kits together.
‘With that, everybody should conduct their lives like business as usual. It’s the weekend. Go out, have a good time.’
Calvo and Trump have discussed the North Korea crisis, with the president pledging to deploy forces that would ensure its territory is safe and secure.