Donald Trump label North Korea as 'rogue nation' that will 'only understand one thing' in a series of tweets posted after  announcement of the "perfect success" of a hydrogen bomb test.

The US President wrote On Twitter: "North Korea has conducted a major Nuclear Test. Their words and actions continue to be very hostile and dangerous to the United States.

"North Korea is a rogue nation which has become a great threat and embarrassment to China, which is trying to help but with little success.

"South Korea is finding, as I have told them, that their talk of appeasement with North Korea will not work, they only understand one thing!"

Meanwhile, Foreign Secretary Boris Johnson said: "There’s no question that this is another provocation. It’s reckless, what they’re doing.