Kim Jong-un has warned America it faces "unimaginable consequences" over sanctions against North Korea.
A government statement published following fresh sanctions against the dictatorship over its arms development programme warns America such actions would only "only heighten the spirit of self-reliance".
It said: "If the US persistently pursues its anachronistic hostile policy toward the North Korea this way, this would only entail unimaginable consequences quite contrary to what the US desires.
North Korea carried out tests on nuclear devices in 2006, 2009 and 2013 and is currently under United Nations sanctions banning trade and financing activities that aid its weapons programme.
A hydrogen bomb, also known as a thermonuclear bomb, uses fusion technology and is the most powerful known weapon on earth - far more powerful than an atomic bomb.
