When Kim Yong Chol lands in New York this week, he will become the most senior North Korean envoy to hold talks with American officials on U.S. soil in 18 years.

The former spy chief is a trusted adviser to North Korean leader Kim Jong Un, playing a pivotal role in preparations for a historic summit between Kim and U.S. President Donald Trump.

In a sign of his importance, Trump announced Kim Yong Chol's New York trip on Twitter on Tuesday.