North Korea claims that a plan that could see it fire four missiles near the US territory of Guam will be ready in a matter of days.
According to state media, Hwasong-12 rockets would pass over Japan and land in the sea about 17 miles from Guam, if the plan was approved by Kim Jong-un.
North Korea denounced President Donald Trump’s warnings of “fire and fury” and said the US leader was “bereft of reason”.
The US has warned North Korea its actions could mean the “end of its regime”.
Defense Secretary Jim Mattis said Pyongyang would be “grossly overmatched” in any war against the US and its allies.
North Korea first announced on August 9 that it had been drawing up plans for a missile strike against Guam, a Pacific island which is home to US military bases, strategic bombers and about 163,000 people.
A later statement carried by state media said the North Korean military would “finally complete the plan” by mid-August and send it to leader Kim Jong-un for his approval.
“The Hwasong-12 rockets to be launched by the KPA [Korean People’s Army] will cross the sky above Shimane, Hiroshima and Koichi [Kochi] Prefectures of Japan,” state news agency KCNA said, quoting army chief General Kim Rak Gyom.
“They will fly 3,356.7km for 1,065 seconds and hit the waters 30-40km away from Guam.”
The Hwasong missiles are North Korea’s domestically produced medium and long-range weapons.
The governor of Guam addressed North Korea’s new statement on August 10, telling Reuters that Pyongyang usually likes to be unpredictable and has fired surprise missiles in the past.
“They’re now telegraphing their punch, which means they don’t want to have any misunderstandings. I think that’s a position of fear,” said Governor Eddie Calvo.
President Trump boasted about America’s atomic arsenal earlier on August 9.
Tweeting from New Jersey where he is on holiday, President Trump said the US nuclear stockpile was “more powerful than ever before”.