Pyongyang’s state-run KCNA news agency issued an update on its strike plans after Trump’s incendiary comments that threats to the US from Pyongyang would be met with “fire and fury”.

Trump’s unexpected remarks prompted North Korea to say it was considering plans to fire four intermediate-range missiles to land 30-40km from Guam, home to about 163,000 people and a US military base that includes a submarine squadron, an air base and a coast guard group.

The army will complete its plans in mid-August, ready for North Korean leader Kim Jong Un’s order, KCNA said, citing General Kim Rak Gyom, commander of the Strategic Force of the Korean People’s Army.

The news agency said Trump “let out a load of nonsense about ‘fire and fury’,” adding “sound dialogue is not possible with such a guy bereft of reason and only absolute force can work on him”.

It came after US Defense Secretary Jim Mattis told Pyongyang it should stop any actions that would lead to the “end of its regime and the destruction of its people”.

Mattis’ words, some of the strongest he has issued on North Korea, followed rising tension in the region since North Korea carried out two nuclear bomb tests last year and two intercontinental ballistic missile tests in July.

Overnight, Australian time, Trump boasted via Twitter of the strength of US nuclear weapons, but hoped they would never need to be used.

My first order as President was to renovate and modernize our nuclear arsenal. It is now far stronger and more powerful than ever before….

— Donald J. Trump (@realDonaldTrump) August 9, 2017

…Hopefully we will never have to use this power, but there will never be a time that we are not the most powerful nation in the world!

— Donald J. Trump (@realDonaldTrump) August 9, 2017

Earlier US Secretary of State Rex Tillerson arrived in Guam on a scheduled visit and told reporters he did not believe there was an imminent threat and “Americans should sleep well at night”.

Trump was “sending a strong message to North Korea in language that (North Korean leader) Kim Jong Un would understand,” Tillerson said.

A senior administration official who deals with the Korea issue said Trump’s comment was “unplanned and spontaneous”.

“There had not been any discussions about escalating the rhetoric in response to Kim’s statements or about the possible effects of doing that,” the official said.

They added, however, “it is important for the North Koreans to understand that this country’s strategic patience is exhausted and that our resolve to defend our allies, whatever is required to do that, is not”.

North Korea regularly threatens to destroy the United States.

North Korea said it was “carefully examining” a plan to strike Guam, which is home to about 163,000 people and a US military base that includes a submarine squadron, an airbase and a Coast Guard group.

Guam Governor Eddie Calvo dismissed the threat and said the island was prepared for “any eventuality”.

North Korea, pursuing missile and nuclear weapons programs in defiance of UN Security Council resolutions, accuses the Washington of devising a “preventive war” and has said any plans to execute this would be met with an “all-out war, wiping out all the strongholds of enemies, including the US mainland”.

Washington has warned it is ready to use force if needed to stop North Korea’s ballistic missile and nuclear programs.

China, which is North Korea’s closest ally despite its anger at Pyongyang’s missile and nuclear programs, described the situation as “complex and sensitive,” and urged calm and a return to talks.

United Nations Secretary-General Antonio Guterres is troubled by the “increase in confrontational rhetoric” on North Korea, a spokesman said.

Russia’s ambassador to the UN called for political dialogue to ease tensions, saying “a military solution is not an option anyway”.

“Our strong wish is that the United States keeps calm and refrains from any moves that would provoke another party to actions that might be dangerous,” Vassily Nebenzia told reporters.

– Reuters