Seoul / Guam: North Korea dismissed on Thursday warnings by U.S. president Donald Trump that it would face "fire and fury" if it threatened the United States as a "load of nonsense", and outlined detailed plans for a missile strike near the Pacific territory of Guam.
North Korea's apparently rapid progress in developing nuclear weapons and missiles capable of reaching the U.S. mainland has fueled tensions that erupted into a war of words between Washington and Pyongyang this week, unnerving regional powers and global investors.
Trump's unexpected remarks prompted North Korea to say on Thursday it was finalizing plans to fire four intermediate-range missiles over Japan to land 30-40 km (18-25 miles) from Guam, adding detail to a plan first announced on Wednesday.
Guam, more than 3,000 km (2,000 miles) to the southeast of North Korea, is home to about 163,000 people and a U.S. military base that includes a submarine squadron, an air base and a Coast Guard group.
"Sound dialogue is not possible with such a guy bereft of reason and only absolute force can work on him," a report by the North's state-run KCNA news agency said of Trump.
The army will complete its plans in mid-August, ready for North Korean leader Kim Jong Un's order, KCNA reported, citing general Kim Rak Gyom, commander of the Strategic Force of the Korean People's Army.
While North Korea regularly threatens to destroy the United States and its allies, the report was unusual in its detail.
Masao Okonogi, professor emeritus at Japan's Keio University, said before the latest KCNA report that Pyongyang may be issuing a warning or advance notice of changes to its missile testing programme rather than threatening an attack.
"I believe this is a message saying they plan to move missile tests from the Sea of Japan to areas around Guam," he told Reuters. "By making this advance notice, they are also sending a tacit message that what they are going to do is not a actual attack."
Japan could legally intercept a North Korean missile headed towards Guam if it posed an existential threat, Defence Minister Itsunori Onodera said on Thursday in remarks reported by Kyodo news service, a reiteration of Tokyo's position.
However, experts say Japan does not currently have the capability to shoot down a missile flying over its territory headed for Guam.
Experts also said the detail provided by North Korea made it likely it would follow through with its plans to avoid being seen as weak or lacking in resolve.
Guam governor Eddie Calvo said there was no heightened threat from North Korea.
"They like to be unpredictable, they'll pop a missile off when no one is ready and they've done it quite a few times. Now they've telegraphed it," he told Reuters in an interview.
"They're now telegraphing their punch, which means they don't want to have any misunderstandings. I think that's a position of fear," he said.
With defenses covering South Korea and Japan, naval assets between Korea, Japan and Guam, and Guam's own missile defense system, there was a "multi-level defensive umbrella" protecting residents, Calvo said.
The United States and South Korea remain technically still at war with North Korea after the 1950-53 Korean conflict ended with a truce, not a peace treaty.
Tension in the region has risen since North Korea carried out two nuclear bomb tests last year and two intercontinental ballistic missile tests in July. Trump has said he will not allow Pyongyang to develop a nuclear weapon capable of hitting the United States.