North Korea’s vow to strike this U.S. Pacific territory with ballistic missiles that could potentially be armed with nuclear warheads has this island in the cross hairs and its 160,000 residents, most of whom are U.S. citizens, on edge.

“I mean, obviously for me, because I’m a father, it’s really concerning,” said 29-year-old Guam resident Jacob Martinez.

That concern was underscored Friday by Guam Homeland Security spokeswoman Jenna Gaminde, who said island residents would have just 14 minutes to take cover once North Korea fired the four promised ballistic missiles.

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“There is not a whole lot we can do,” said John Bell, who’d just arrived in Guam from a week in San Diego. “If we are going to get nuked, nothing I do or say is going to change anything.”

Guam Homeland Security spokeswoman Jenna Gaminde said island residents would have just 14 minutes to take cover once North Korea fired the four promised ballistic missiles. (Reuters)

Residents offered a range of opinions, from resignation and complacency to anxiety and fear. But, more than anything, residents said they felt unsettled.

“It is a little concerning,” said a woman visiting Guam for the first time from Ohio. “I think when the two heads of state get together, I hope they won’t do anything stupid.”

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On Wednesday, in response to a statement by President Trump, North Korea’s official state-run news agency, KCNA, said its military is "examining the operational plan" to strike areas around Guam with four medium-range ballistic missiles. It said the plan would be ready in mid-August, and the missiles would splashdown 18 to 25 miles from shore after a 17-second flight.

One of two U.S. Air Force B-1B Lancer aircraft is refueled during a mission to fly in the vicinity of Kyushu, Japan, the East China Sea, and the Korean peninsula June 20, 2017. North Korea is setting its sites on Guam because it has two key military bases the U.S. uses to conduct exercises in Southeast Asia (U.S. Air Force/Airman 1st Class Gerald R. Willis/Handout via REUTERS)

Guam may be vulnerable but it is not defenseless. As “the tip of the spear,” as Guam is often called, the island is the closest U.S. territory to North Korea, 2,100 miles away compared to almost 6,000 miles from Hawaii and San Francisco.

North Korea is focusing on Guam because it has two key military bases the U.S. uses to conduct exercises in Southeast Asia. One is Andersen Air Force Base, used by U.S. heavy bombers, nuclear and conventional, to overfly the Korean peninsula. The other is the U.S. Naval Base Guam, where four nuclear submarines are based, along with other warships, including Aegis class destroyers, which carry an advanced anti-missile defense system.

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That, along with a land-based system called THAAD, protect Guam. The missile interceptor system was installed in 2013 after Kim Jong-un said he had Andersen in his sights. Guam also holds the world’s largest stockpile of weapons, according to an Andersen fact sheet.

As “the tip of the spear,” as Guam is often called, the island is the closest U.S. territory to North Korea, 2,100 miles away compared to almost 6,000 miles from Hawaii and San Francisco. (Fox News)

“I don’t sense people are scared,” says Lee Weber, former publisher of the Pacific News newspaper. “They know our nation has a strong defense and the military will watch over us, take care of us.”

Guam Gov. Eddie Calvo agreed, telling residents Wednesday they had nothing to worry about because Washington assured him it would defend Guam, an island 30 miles long and just 2- to 12-miles wide, or roughly nine times larger than Manhattan.

“At this point there has been no change in the threat level, either on a military base in Guam or in our civilian community,” Calvo told reporters at a news conference.

The governor’s office, however, did distribute a fact sheet to residents telling them what to do in case of an “imminent missile strike.” It tells them to avoid looking at a fireball since it can blind you, stay inside concrete block buildings and remove any clothing that may be contaminated with radioactive fallout.

Andersen Air Force Base in Guam is used by U.S. heavy bombers, nuclear and conventional, to overfly the Korean peninsula. (AP)

That doesn’t sound like much of a tourist billboard. Yet, according to the Chamber of Commerce, there have been only a few cancellations.

“People are talking about Guam all over the world,” says Carl Peterson, of the chambers’ Armed Forces Committee. “They know where Guam is now. We think that is good PR for us.”