US bombers on Saturday flew further north of the Korean Demilitarised Zone than ever before this century, staging a show of force as North Korea’s foreign minister warned that the US was pushing them closer towards retaliation.

Ri Yong-ho, speaking at the United Nations general assembly, described President Donald Trump as “an old gambler” who "has tried to turn the UN arena into a gangsters' nest where money is respected and bloodshed the order of the day."

“He committed an irreversible mistake of making our rockets' visit to the entire US mainland inevitable all the more,” said Mr Ri, referencing Mr Trump’s speech on Tuesday at the UN.

"What else could be a bigger threat than the violent remarks such as pouring 'fire and fury', 'total destruction' coming from the top authority of the world's biggest nuclear power.

"The very reason the DPRK had to possess nuclear weapons is because of the US and it had to strengthen and develop its nuclear force onto the current level to cope with the US."

The Pentagon said the flight was in response to the "grave threat" that North Korea posed to the Asia-Pacific region, and the international community.

"This is the farthest north of the Demilitarized Zone (DMZ) any US fighter or bomber aircraft have flown off North Korea's coast in the 21st century, underscoring the seriousness with which we take (North Korea's) reckless behavior," said Dana White, spokesman for the Pentagon.