[NOTE TO EDITORS: THIS UPDATES PREVIOUS PIECE FOLLOWING WHITE HOUSE STATEMENT]
US President Donald Trump has referred to the North Korean leader Kim Jong Un as "Rocket Man" in a posting on the social media site Twitter.
The White House says he spoke on Saturday night with South Korea's President, and the two men plan to discuss the crisis on the Korean Peninsula in New York later this week.
Our US Correspondent Simon Marks reports.
IN: "The call…."
OUT: "….spark conflict"
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