The UK Foreign Secretary has suggested that North Korea was holding "the nuclear sword of Damocles" over "a trembling human race."

Boris Johnson also said US President Donald Trump had an "absolute duty" to respond to North Korea's nuclear threats in any way necessary.

Boris Johnson also encouraged the US to push for dialogue with Pyongyang.

He also praised the Iran nuclear deal.

Trump has repeatedly criticised the Iran deal and refused to negotiate with North Korea.





The British Foreign Secretary has likened the North Korean crisis to a Classical myth, and thrown his weight behind US President Donald Trump's military threats against North Korea.

In a keynote speech at the Chatham House conference in London on Monday, Boris Johnson said Trump has an "absolute duty" to protect Americans from a nuclear attack from Pyongyang, but urged the US to continue pushing for negotiations.

"It is this increased tempo of nuclear testing, coupled with florid outbursts of verbal belligerence, that have reawakened, even in this conutry, those forgotten fears" of nuclear attacks, Johnson told the conference.

"The public can be forgiven for genuinely starting to wonder whether the nuclear sword of Damocles is once again held over the head of a trembling human race."

The sword of Damocles is an ancient myth, which demonstrated the fragility of power by imaging a king sitting on a throne with a sword permanently suspended above his head by a single thread. In modern usage it has come to refer to any kind of impending danger.

Johnson added:

"Kim and the world need to understand that when the 45th President of the United States contemplates a regime led by a man who not only threatens to reduce New York to 'ashes,' but who stands on the verge of acquiring the power to make good on his threat.

"I am afraid that the US President — whoever he or she might be — will have an absolute duty to prepare any option to keep safe not only the American people but all those who have sheltered under the American nuclear umbrella."

North Korea has tested 19 missiles and has conducted four of the six nuclear tests ever carried out by that country this year alone, Johnson said.

A man in Seoul, South Korea watches a news bulletin showing US President Donald Trump and North Korean leader Kim Jong Un. Ahn Young-joon/AP

The Foreign Secretary backed US Secretary of State Rex Tillerson's push for dialogue with Pyongyang. Earlier this month, Trump said Tillerson was "wasting his time" trying to negotiate with North Korea.

On Sunday, Trump boasted that the US was "totally prepared" to respond to any North Korean aggression.

"We are so prepared, like you wouldn't believe," he told Fox Business Network, as cited by CNN. "You would be shocked to see how totally prepared we are if we need to be."

Earlier this month, the Daily Mail reported that British military officials had secretly started outlining plans for war with North Korea.

Johnson backs the Iran deal

Johnson also highlighted the success of the Iran nuclear treaty, a deal orchestrated by former President Barack Obama that Trump has repeatedly criticised and threatened to rip up. He said:

"That is the model — of toughness but engagement, each reinforcing the other — that we should have at the front of our mind as we try to resolve the tensions in the Korean peninsula," Johnson said. "It is right that Rex Tillerson has specifically opened the door to dialogue."

"This is the moment for North Korea’s regime to change course — and, if they do, the world can show that it is once again capable of the diplomatic imagination that produced the nuclear non-proliferation treaty — arduously negotiated — and that after 12 years of continuous effort produced the JCPOA [Joint Comprehensive Plan of Action] nuclear deal with Iran."