President Donald Trump said North Korea will be met with “fire and fury like the world has never seen” after US intelligence concluded the rogue state has produced a miniaturised nuclear warhead that can fit inside an intercontinental ballistic missile.
Kim Jong-un reached the watershed moment much quicker than expected and he now also now has up to 60 nuclear warheads, significantly more than previously thought.
Mr Trump said: “He has been very threatening, beyond a normal statement. North Korea best not make any more threats to the United States.
“They will be met with fire and fury and frankly power, the likes of which the world has never seen before.”
North Korea said on Tuesday night it was “carefully examining” a plan to strike the US territory of Guam with missiles.
The plan will be “put into practice in a multi-current and consecutive way any moment”, a spokesman for the regime said.
It emerged days after US officials also revealed they believe North Korea will have the capability to successfully launch a nuclear capable ICBM by next year.
The hermit kingdom still needs to develop a working atmospheric re-entry vehicle to protect the warhead.
The latest development will increase pressure on US President Donald Trump to decide how to respond to the growing threat.
A section of the latest DIA report, which was dated July 28, was read over the telephone to the Washington Post by an official.
The report said: “The intelligence community assesses North Korea has produced nuclear weapons for ballistic missile delivery, to include delivery by ICBM-class missiles.”
It was not known if North Korea has successfully tested the miniaturised warhead design.
Last year it claimed to have tested such a device but experts had remained dubious.
On the same day as the US report was disclosed Japan also said it believed North Korea may have developed miniaturised nuclear warheads.
In its annual Defence White Paper, Japan said: “It is possible that North Korea has already achieved the miniaturisation of nuclear weapons and has acquired nuclear warheads.
“Since last year, when it forcibly implemented two nuclear tests and more than 20 ballistic missile launches, the security threats have entered a new stage.”
Last month North Korea conducted two ICBM tests, showing the potential range to hit most of the continental US.
At the weekend the United Nations imposed its toughest sanctions yet on North Korea.
But the regime said the sanctions would not stop it from developing its nuclear arsenal, rejecting talks and angrily threatening retaliation against the US.
Hours before the new assessment was disclosed Mr Trump praised the UN sanctions,
He said on Twitter: “After many years of failure,countries are coming together to finally address the dangers posed by North Korea. We must be tough & decisive!”
Mr Trump has said “all options are on the table” to deal with the North Korean threat.
Rex Tillerson, the US Secretary of State, has left the potential for dialogue open, saying the Washington could talk to Pyongyang if it stops missile tests.