About the Author
Leo Byrne
Leo Byrne was the Data and Analytic Director at NK News. Follow him on twitter.
Washington on Friday said the North Korean government had used chemical weapons in violation of international laws in a notice posted on the U.S. government's Federal Register.
The notice was added by the U.S. State Department's Bureau of International Security and Nonproliferation, though it did not give further details on how Washington had arrived at the conclusion.