The US military has flown bombers close to North Korea to show Pyongyang that Donald Trump “has many military options to defeat any threat.”

The show of force follows a contentious week in which Mr Trump and North Korean leader Kim Jong-un exchanged personal barbs over North Korea’s nuclear ambitions. The comments marked an escalation in rhetorical warfare that has already seen Mr Trump promise “fire and fury” if North Korea does not curb its pursuit of nuclear weapons that could hit America.

Earlier on Saturday an earthquake was detected near the site where North Korea has conducted numerous nuclear tests, sparking fears of a new detonation. But later analysis suggested the tremor was natural in origin.

Mr Trump used his first address to the UN to say that “Rocket man is on a suicide mission,” using a nickname he coined for Mr Kim. In response, Mr Kim issued an unprecedented personal statement, and referred to the President as a “dotard” — a word used to describe old and senile individuals.

“Now that Trump has denied the existence of and insulted me and my country in front of the eyes of the world and made the most ferocious declaration of a war in history that he would destroy [North Korea], we will consider with seriousness exercising of a corresponding, highest level of hardline countermeasure in history,” Mr Kim said in that statement.

His foreign minister has now said that Mr Trump is trying to convert the UN into a “gangsters nest” where “bloodshed is order of the day”.

North Korean officials have said that Mr Kim is considering green lighting a nuclear test in the Pacific Ocean in response to Mr Trump’s comments, just weeks after the country’s sixth and most powerful nuclear test to date. Just days later, seismologists detected a 3.5 magnitude earthquake near North Korea’s known nuclear testing site — however it wasn’t immediately clear if that quake was a man-made occurrence from an explosion, or naturally occurring.

Kim Jong-un inspects weapon North Korea says is powerful hydrogen bomb Show all 6 1 /6 Kim Jong-un inspects weapon North Korea says is powerful hydrogen bomb Kim Jong-un inspects weapon North Korea says is powerful hydrogen bomb Photos released by North Korea show Kim Jong-un talking to subordinates next to a device thought to be the new thermonuclear weapon. There is no way of independently verifying the pictures STR/AFP/Getty Images Kim Jong-un inspects weapon North Korea says is powerful hydrogen bomb North Korea claims it has successfully tested an advanced hydrogen bomb which could be loaded onto an intercontinental ballistic missile AFP/Getty Kim Jong-un inspects weapon North Korea says is powerful hydrogen bomb A diagram on the wall behind Mr Kim shows a bomb mounted inside a cone STR/AFP/Getty Images Kim Jong-un inspects weapon North Korea says is powerful hydrogen bomb North Korean leader Kim Jong-Un (C) attending a photo session with participants of the fourth conference of active secretaries of primary organisations of the youth league of the Korean People's Army (KPA) in Pyongyang STR/AFP/Getty Images Kim Jong-un inspects weapon North Korea says is powerful hydrogen bomb A new stamp issued in commemoration of the successful second test launch of the "Hwasong-14" intercontinental ballistic missile KCNA via Reuters Kim Jong-un inspects weapon North Korea says is powerful hydrogen bomb A new stamp issued in commemoration of the successful second test launch of the "Hwasong-14" intercontinental ballistic missile KCNA via Reuters

“This event occurred in the area of the previous North Korean Nuclear tests,” the United States Geological Survey said on its web site. “We cannot conclusively confirm at this time the nature of the event.”