North Korea has revealed a detailed plan to fire four missiles at the US territory of Guam, and hit back at President Donald Trump's "fire and fury" threat by calling it a "load of nonsense", even as its neighbours vowed to take action if further provoked.
Japan's Defence Ministry warned that it could legally intercept such a missile launch, while South Korea's Joint Chiefs of Staff said North Korea will face "strong and resolute retaliation" from the allies if it continues with provocations.
US Defence Secretary James Mattis also issued a strong warning to North Korea to "cease any consideration of actions that would lead to the end of its regime and the destruction of its people".
Earlier in the week, Mr Trump said North Korea would face "fire and fury like the world has never seen" if Pyongyang continues to provoke, then boasted on Twitter that the US nuclear arsenal is "far stronger and more powerful than ever before".
North Korean commander Kim Rak Gyom retaliated yesterday in comments carried in state media Korean Central News Agency (KCNA), saying "sound dialogue is not possible with such a guy bereft of reason and only absolute force can work on him".
The same report gave unusually specific details of North Korea's plan to launch four Hwasong-12 intermediate-range missiles on a flight of 18 minutes across Japanese skies to land in waters surrounding Guam, about 30km to 40km away from land. Guam, a tropical island, smaller than Singapore and more than 3,000km to the south-east of North Korea, is home to a major US Navy installation that includes a submarine squadron, a Coast Guard group and an air base.
North Korea's Strategic Force said the plan will be finalised by mid-August, and is subject to North Korean leader Kim Jong Un's approval. It aimed to "interdict the enemy forces" in Guam's major military bases, and to "signal a crucial warning to the US", said KCNA.
The escalating rhetoric raised concerns that any miscalculation could trigger a catastrophe. About 40 per cent ( some 64,000) of Guam's population of 162,000 are Filipinos. A Philippine presidential spokesman said on TV yesterday that there are "contingency plans" in place against North Korean threats.
Tensions grew after North Korea made major advances in its nuclear programme by testing two intercontinental ballistic missiles last month. Analysts warned the situation could worsen as Seoul and Washington gear up for the next round of joint military drills later this month, which irk Pyongyang.
South Korea urged calm. The country's National Security Council, after a regular meeting yesterday, noted that the situation was "becoming serious", and called on the North to "immediately stop all activities" and return to dialogue.
Seoul Mayor Park Won Soon also expressed wishes to visit Pyongyang to promote unification.
There was no official response from China. But the state-run China Daily urged efforts to persuade the United States and North Korea to "take a step back from the brink".
South Korean analyst Lee Sang Hyun from the Sejong Institute think-tank told The Straits Times that both the US and North Korea are issuing "maximum threats" to each other, a situation that can continue for weeks, or even months.
"But carrying out physical attacks is a different issue," he said. "Right now, it is just a war of words, rather than actual warfare."