North Korea threatens to detonate hydrogen bomb in Pacific Ocean after Donald Trump speech

US President threatened to 'totally destroy' North Korea

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.

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".

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.

The claimed nuclear test earlier in September also caused tremors in China and prompted wave of anxiety throughout the region.