North Korea has suggested it could detonate a nuclear bomb in the Pacific Ocean, in response to an inflammatory debut United Nations speech by President Donald Trump.

The foreign minister for North Korea, Ri Yong Ho, said his government would consider a hydrogen bomb test of an unprecedented scale in the sea, but added that such a decision would ultimately be taken by the country's ruler, Kim Jong-un.

His remarks came shortly after the North Korean state news agency released a transcript of a rare personal statement by Mr Kim, in which he hit back at the US president's "deranged" address at the UN.

Mr Trump's threat to "totally destroy" North Korea and impose new sanctions had "convinced" him he was right to continue developing nuclear weapons, Mr Kim said.

Speaking in New York, Mr Ri said his country would continue to escalate its weapons tests, after a claimed hydrogen bomb detonation near Pyongyang earlier this month.

“It could be the most powerful detonation of an H-bomb in the Pacific," he said.

“We have no idea about what actions could be taken as it will be ordered by leader Kim Jong-un.”

Similar above-ground tests have not been conducted since the Cold War and North Korea's nuclear detonations have all been occurred underground.

It would be an "exceedingly provocative" move, according to Vipin Narang, an associate professor of political science at Massachusetts Institute of Technology.

He said: "To put a live nuclear warhead on a missile that's only been tested a handful of times, overflying potentially populated centres. If it...doesn't go exactly as planned... it could be a world changing event."

There are also concerns about the potential for radioactive fallout in the blast zone.

Trump: US will 'totally destroy' North Korea 'if forced to'

China, North Korea's ally and arbiter of stability in the region, called on all parties to exercise restraint after the incendiary remarks.

"No matter the changes in circumstance, no matter how long it takes, not matter the difficulties we face, China will always persist in the goal of denuclearising the [Korean] peninsula, in moving towards talks," said Foreign Minister Wang Yi at the UN on Thursday.

Russia, which has lines of communication with North Korea, said it was deeply concerned by the escalation of tensions on the peninsula.

A Kremlin spokesman said it was caused by an exchange of "relatively stupid pronouncements".

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

Relations between North Korea and the US have dramatically deteriorated up in recent months, prompted by a series of missile launches by North Korea, in contravention of international rules.

Japan and South Korea, "ironclad" allies of the US, have been especially unnerved by the tests and often hold drills in preparation for an attack.