North Korea tests an H-bomb - level 3
North Korea says it has successfully conducted a test of a miniaturised hydrogen bomb. The announcement on North Korean state TV followed the detection of a 5.1 magnitude earthquake near its known nuclear site.
The channel released these photographs of leader Kim Jong Un signing the order approving the trial. If true, this would be the fourth nuclear test by the isolated country, which is under US and UN sanctions for its nuclear and missiles programmes.
The US Geological Survey said the recording was bigger than the three previous bombs the country tested in 2013, 2009 and 2006.
North Korea said it would continue to strengthen its nuclear programme in order to protect itself against the hostile policies of the US. It also said it would act as a responsible nuclear state, vowing not to use its nuclear weapons unless its sovereignty was infringed or transfer its nuclear capabilities to other parties.
While it could not confirm the claims, the White House stated that the US would continue to "protect and defend" its allies in the region and "respond appropriately to any and all of North Korean provocations."
Leaders across the world have also responded to the news. The Japanese Prime Minister said the nation could not tolerate North Korea's nuclear testing, branding it a threat to Japan's security. The British Foreign Secretary Philip Hammond tweeted a response, saying the test would be a "grave breach of UN Security Council resolutions".
Difficult words: conduct (to carry out), announcement (a formal public statement), detection (measurement), magnitude (strength), hostile (unfriendly), policy (a principle of action), vow (to promise), sovereignty (authority), infringe to (try to destroy), party (a group of people), provocation (an attempt to upset someone), grave (serious), breach (breaking a law), resolution (an opinion – what you want or do not want).
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