North Korea's military is "examining the operational plan" to strike areas around the US territory of Guam with medium-to-long-range strategic ballistic missiles, state-run news agency KCNA said early Wednesday local time.
Specifically, the statement mentioned a potential strike on Andersen Air Force Base designed "to send a serious warning signal to the US."
The base is one of two on the Pacific island, which are the closest bases on US soil to North Korea, and represent westernmost tip of the country's military might.
The North Korea comments were published after US President Donald Trump warned Pyongyang that if it continued to threaten the US, it would "face fire and fury like the world has never seen."
However, the statement was dated Tuesday, suggesting the text was written before Trump's latest spray.
Guam's governor, Eddie Baza Calvo, released a video address Wednesday, reassuring the island's residents that there was no escalated threat.
"I want to reassure the people of Guam that currently there is no threat to our island or the Marianas," he said.
"My Homeland Security Advisor who is in communications with Homeland Security and Department of Defense notes that there is no change in threat level resulting from North Korea events. HSA George Charfauros reminds us that there are several levels of defense all strategically placed to protect our island and our nation.
"I also want to remind national media that Guam is American soil and we have 200,000 Americans in Guam and the Marianas. We are not just a military installation."
The US Department of Defense reiterated its capability to counter North Korean aggression.
"We always maintain a high state of readiness and have the capabilities to counter any threat, to include those from North Korea," spokesman Johnny Michael told CNN.
Escalating tensionsNorth Korea ramped up the rhetoric in a new statement issued Wednesday, sourced to a spokesman for the General Staff of the Korean People's Army (KPA), which said a "preemptive strike is no longer the monopoly of the US."
Pyongyang's initial threat to Guam came after the US flew two B-1B bombers over the Korean peninsula on Monday.
The bombers flew out of Anderson Air Force Base in Guam as part of the US Air Force's "continuous bomber presence", according to an Pacific Air Forces spokesman. The bombers were joined by Japanese and South Korean aircraft during their mission.
"In the morning of August 8 the air pirates of Guam again appeared in the sky above South Korea to stage a mad-cap drill simulating an actual war," the KCNA statement read.
Key military installationDubbed the "Tip of the Spear," Guam is a key to the US military's forward deployed presence in the Pacific and is home to thousands of American service members and their families.
Should the US retaliate to Kim's latest threats, its position makes the US territory the most likely place from which to launch airstrikes on North Korea.
A US attack using its bases on Japan's main islands or Okinawa, for example, would bring Japan into any conflict, says Carl Schuster, a Hawaii Pacific University professor and former director of operations at the US Pacific Command's Joint Intelligence Center.
Source: CNN