Seoul: North Korea executed its special envoy to the United States following the collapse of the second summit between leader Kim Jong Un and US President Donald Trump, a South Korean newspaper reported on Friday.

The Chosun Ilbo said Kim Hyok Chol, who laid the groundwork for the Hanoi meeting and accompanied Kim on his private train, was executed by firing squad for "betraying the supreme leader" after he was "won over to the US" during pre-summit negotiations. "Kim Hyok Chol was executed in March at Mirim Airport along with four senior foreign ministry officials following an investigation," the newspaper quoted a source as saying.