North Korean leader Kim Jong Un supervised tests of short-range ballistic missile systems that simulated nuclear counterstrikes against U.S. and South Korean forces, state media said Friday, as the North continued to blame its rivals for escalating tensions through their joint military exercises.

It was the first known ballistic missile test by North Korea since 10 March when it fired a number of short range missiles, after US and South Korean troops began an annual combined military exercise, and the country's sixth launch event of the year.