DONALD Trump has added economic sanctions to his fiery military threats to North Korea and ramped up his rhetoric against Kim Jong Un, calling the reclusive leader “obviously a madman”.

The US President’s move to punish foreign companies that deal with the North was the latest salvo in a US-led campaign to isolate and impoverish Mr Kim’s government until his country halts its missile and nuclear tests.

Mr Trump announced the measures as he met leaders from South Korea and Japan, the nations most immediately endangered by North Korea’s threats of a military strike.

“North Korea’s nuclear weapons and missile development is a grave threat to peace and security in our world and it is unacceptable that others financially support this criminal, rogue regime,” Mr Trump said as he joined Japanese Prime Minister Shinzo Abe and South Korean President Moon Jae-in for lunch. “Tolerance for this disgraceful practice must end now.”

Hours later, Mr Kim branded him as “deranged” and warned that he will “pay dearly” for his threat to “totally destroy” the North if it attacks US interests.

The rare statement from the North Korean leader responded to Mr Trump’s combative speech days earlier when he issued a warning of potential obliteration for the isolated nation, and mocked the North’s young autocrat as a “rocket man”

on a “suicide mission”.

Returning insult with insult, Mr Kim said the President was “unfit to hold the prerogative of supreme command of a country”.

He described the President as “a rogue and a gangster fond of playing with fire”, and characterised Mr Trump’s speech to the world body on Tuesday as “mentally deranged behaviour”.

The volley of insults continued yesterday as Mr Trump sent out a pre-dawn Twitter post: “Kim Jong Un of North Korea, who is obviously a madman who doesn’t mind starving or killing his people, will be tested like never before!” the President tweeted.

North Korea’s foreign minister reportedly said his country may test a hydrogen bomb in the Pacific Ocean.

Ri Yong Ho told reporters in New York that Pyongyang’s response “could be the most powerful detonation of an H-bomb in the Pacific”, according to South Korean media.

The Yonhap news agency said the foreign minister added: “We have no idea about what actions could be taken as it will be ordered by leader Kim Jong Un.”

Mr Trump’s executive order expanded the Treasury Department’s ability to target anyone conducting significant trade in goods, services or technology with North Korea, and to ban them from interacting with the US financial system.

Mr Trump also said China was imposing major banking sanctions, but there was no immediate confirmation from the North’s most important trading partner.

Meanwhile, the President has called allegations of Russian meddling in the US presidential election a “hoax” and insisted the media was the “greatest influence” on last year’s campaign.

Mr Trump’s tweets appeared to respond to Facebook’s announcement that the social media giant will hand congressional investigators the contents of 3,000 adverts bought by a Russian agency.

“The Russia hoax continues, now it’s ads on Facebook. What about the totally biased and dishonest Media coverage in favor of Crooked Hillary?”

The president later added: “The greatest influence over our election was the Fake News Media ‘screaming’ for Crooked Hillary Clinton. Next, she was a bad candidate!”

Facebook has faced growing pressure from members of Congress to release the content of the adverts.

The company has already handed over the adverts to the special counsel investigating Russian interference in the election.

Facebook said it will now require political adverts to disclose who is paying for them and all advert campaigns those individuals or groups are running on Facebook.

The Herald:

ANALYSIS: Threats, insults and put-downs… how the leaders have sunk to new lows

By Jessic Estepa

US President Donald Trump and North Korea’s leader Kim Jong Un have traded barbs throughout 2017.

The exchanges, often on Twitter, have included nicknames and new vocabulary, whilst also openly suggest war and destruction. As tensions rose over North Korea’s ongoing missiles testing, Mr Trump threatened that he would send the military to handle the situation.

The President told Fox Business in April: “We are sending an armada. Very powerful. We have submarines.

Very powerful, far more powerful than the aircraft carrier, that I can tell you.”

But in fact the fleet was actually 3,000 miles away from the Korean peninsula.

On April 28, Mr Trump suggested that a “major, major conflict” between the two countries was possible, because of North Korea’s ongoing development of its nuclear and ballistic missiles program.

While Mr Trump then said he would be willing to meet with Mr Kim under the “right circumstances” and called the leader a “smart cookie”, North Korea said it would up its nuclear testing to its “maximum pace” over sanctions. After the regime launched its first intercontinental ballistic missile in early July, Mr Trump jabbed at trade between China and North Korea, saying that it had risen.

After the sanctions against North Korea were in place, the regime said: “The US’s villainous illegal actions against our country and people will be reciprocated by thousands-fold.

If it thinks that it will be safe because it is across an ocean, there is no bigger misunderstanding than that.”

The country then threatened the Guam, leading Mr Trump to say: “They will be met with fire and fury and frankly power, the likes of which this world has never seen before.” North Korean General Kim Rak Gyom said: “Sound dialogue is not possible with such a guy bereft of reason and only absolute force can work on him.”

Mr Trump first branded Mr Kim “Rocket Man” in September before returning to it at UN General Assembly this week.

Mr Kim replied to the President’s UN threats calling Mr Trump a “frightened dog”

adding: “I will surely and definitely tame the mentally deranged US dotard [a senile person] with fire.” It didn’t end there, with Mr Trump responding in kind yesterday.

This is an abridged version of politics writer Jessica Estepa’s article in USA Today