The United States is attempting to check on reports that a senior North Korean official involved in Pyongyang’s non proliferation talks with Washington has been executed, Secretary of State Mike Pompeo said on Friday.

“We’ve seen the reporting to which you are referring,” Pompeo told a news conference in Berlin in answer to a reporter’s question. “We’re doing our best to check it out. I don’t have anything else to add to that today.”

Earlier on Friday nuclear envoy Kim Hyok Choi had been executed as part of a purge of officials who steered negotiations for a failed summit between leader Kim Jong Un and US President Donald Trump.