|Why is North Korea threatening to strike Guam with missiles?|
But where is the island and why is it a potential target?
Since it became an American territory in 1898, Guam has been considered a vital asset by Washington.
It lies in the Pacific east of the Philippines and around 1,700 miles south of North Korea.
Its proximity to China, Japan and the Korean Peninsula hand the US a launching pad into Asia and as such it has been built up into a military fortress.
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North Korea lies around 1,700 miles from Guam
The US runs a naval base and Coast Guard station in the south of the island, as well as an air force base in the north which was regularly used during the Vietnam War.
Based at the stations are around 6,000 US troops, with the military second only to tourism in terms of net contribution to Guam's economy.
The bases cover 30% of the entire island, which is roughly the size of Chicago and has a population of 162,000.
While it gives the US the capability to launch strikes in Asia, Guam also serves an important defensive function for Washington and its allies.
In 2013, the US Army's Terminal High Altitude Area Defence (THAAD) system was deployed to the island - giving Washington the power to shoot down North Korean ballistic missiles.
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|North Korea lies around 1,700 miles from Guam|
This makes it a target for Pyongyang, as does its remoteness.
Residents on the island described their fears after getting caught in the middle of a war of words between Washington and Pyongyang.
Cecil Chugrad, a 37-year-old bus driver, said: "I'm a little worried, a little panicked. Is this really going to happen?
"If it's just me, I don't mind, but I have to worry about my son. I feel like moving (out of Guam) now."
"I'm not laughing now," he said. "My concern is that things have changed in Washington, and who knows what's going to happen?"
His brother Mitch added he believes many on the island "have no confidence that the White House will do the right thing under the circumstances".
Reacting to North Korea's threat of a military strike, Guam governor Eddie Calvo reminded Americans in mainland USA that the island is "not just a military installation".
He said: "I have reached out to the White House this morning.
"An attack or threat to Guam is a threat or attack on the United States. They have said that America will be defended."