US President Donald Trump on North Korea: They won’t be around much longer

US President Donald Trump (file photo)

Heated exchanges continue between Washington and Pyongyang. US President Donald Trump has reacted to North Korean Foreign Minister Ri Yong-ho's speech at the United Nations with another controversial tweet, apparently irked by his threat of an eventual missile strike on US mainland.

"Just heard Foreign Minister of North Korea speak at U.N.," Trump tweeted late on Saturday. "If he echoes thoughts of Little Rocket Man, they won't be around much longer!"

During a fiery speech before the United Nations General Assembly on Saturday, Ri Yong-ho assailed Trump as “a mentally deranged person full of megalomania” who is holding “the nuclear button.”

The North Korean minister warned that it is “inevitable” that Pyongyang will launch a missile toward the mainland United States in revenge for Trump’s insults against Kim.

Ri also accused Trump of turning the United Nations into a "gangsters' nest where money is respected and bloodshed is the order of the day."

The North Korean nuclear standoff has dominated this year's gathering of world leaders at the United Nations amid fears that the escalating war of words could lead to an actual military confrontation.

North Korea's Foreign Minister Ri Yong-ho is about to address the UN General Assembly, September 23, 2017. (Photo by AFP)

On Tuesday, the US president had used the same forum to mock North Korea’s leader as a “Rocket Man” who is on a “suicide mission.” He also warned that the US would “totally destroy” North Korea if necessary.

The hyperbolic volley of insults continued in the same vein Saturday with Ri saying that, “None other than Trump himself is on a suicide mission.”

Earlier in the day, the Pentagon announced that US bomber and fighter jets flew along North Korea's eastern coastline in a "show of force" that was closer to the North’s border than any other operation this century.

"This mission is a demonstration of US resolve and a clear message that the president has many military options to defeat any threat," Pentagon spokeswoman Dana White said. "We are prepared to use the full range of military capabilities to defend the US homeland and our allies."

The Pentagon issued several photos of the US B-1 bomber and F-15 fighter jets creeping toward the Korean Peninsula.

In his speech, Ri did not mention the flights, but he slammed the “heinous and barbaric” UN sanctions, and said they would not deter North Korea from advancing its nuclear weapons program.

“Through such a prolonged and arduous struggle, now we are finally only a few steps away from the final gate of completion of the state nuclear force,” Ri said.

Earlier in the week, Ri raised the possibility of an atmospheric nuclear test over the Pacific. All of North Korea’s previous nuclear tests have been underground. No country has carried out an atmospheric nuclear test since China did in 1980.

The standoff between North Korea and the US reached its peak after Pyongyang detonated its sixth - and the most powerful - nuclear bomb earlier this month and said the weapon was on the path of completion to fit its intercontinental ballistic missiles.