Kim Jong‑un has said remarks by US President Donald Trump have convinced him he is right to develop weapons for North Korea.
In an unprecedented personal statement, Kim says Trump would "pay dearly" for a UN speech where he threatened to "totally destroy" the North if the US was forced to defend itself.
Trump responded that the "madman... will be tested like never before".
Kim ended his statement by saying he would surely and definitely tame Trump with fire.
China responded to the war of words, warning that the situation was "complicated and sensitive".
China’s Foreign Minister Lu Kang says all relevant parties should exercise restraint instead of provoking each other.
Russia also urged restraint, with Foreign Minister Sergei Lavrov describing the conversation between the two leaders as a "kindergarten fight between children".
North Korea has been testing missiles at an unprecedented rate, and conducted its sixth nuclear test despite international condemnation.
North Korean Foreign Minister Ri Yong‑ho, who had earlier compared Trump's speech to "the sound of a barking dog" has warned that Pyongyang could test a hydrogen bomb in the Pacific Ocean in response to the US president's threat.
Source: BBC
