North Korea nuclear test: Trump condemns 'hostile' move

The US has joined condemnation of North Korea after it tested what it says is a more advanced nuclear weapon.

Pyongyang said it had successfully trialled a hydrogen bomb that could be loaded on to a long-range missile.

President Donald Trump tweeted that North Korea's "words and actions" were "very hostile and dangerous".

North Korea has defied UN sanctions and international pressure to develop nuclear weapons and test missiles that could potentially reach the US.

South Korea, Japan, China and Russia have all voiced strong criticism of the North's sixth nuclear test.

What has happened?

The first suggestion that this was to be a far from normal Sunday in the region came when seismologists' equipment started picking up readings of an earth tremor in the area where North Korea has conducted nuclear tests before.

The US Geological Survey put the tremor at 6.3 magnitude.

Japanese Foreign Minister Taro Kono said there was no doubt this was North Korea's sixth nuclear test, calling it "unforgivable".

Then North Korean state media confirmed this was no earthquake.

It claimed the country had conducted its sixth and most powerful nuclear test, detonating a hydrogen bomb that could be loaded onto a long-range missile.

North Korean leader Kim Jong-un was pictured with what state media said was a new type of hydrogen bomb.

Analysts say North Korea's claims should be treated with caution, but that its nuclear capability is clearly advancing.

Officials in China, where the blast was felt as a tremor, said they were carrying out emergency radiation testing along the border with North Korea.

What has the reaction been?

Denouncing the test as ''hostile'' and ''dangerous'' President Trump described the North as a "rogue nation" which had become a "great threat and embarrassment" to China - Pyongyang's main ally.

He also said South Korea's "talk of appeasement" was not working and that the secretive communist state "only understands one thing".

"The United States is considering, in addition to other options, stopping all trade with any country doing business with North Korea," Mr Trump later said in a tweet.