Ri told the United Nations General Assembly earlier on Saturday that targeting the U.S. mainland with its rockets was inevitable after "Mr Evil President" Trump called Pyongyang's leader "rocket man."
"Just heard Foreign Minister of North Korea speak at U.N. If he echoes thoughts of Little Rocket Man, they won't be around much longer!" Trump tweeted.
https://www.cnbc.com/2017/09/24/trump-tweets-threats-to-north-korea-after-un-speech-by-rogue-nations-foreign-minister.html