This satellite image released and notated by Airbus Defense & Space and 38 North on April 12, 2017, shows the Punggye-ri nuclear test site in North Korea. North Korean leader Kim Jong Un vowed to shut down his country's nuclear test site in May 2018 and disclose the process to experts and journalists from South Korea and the United States, Seoul's presidential office said Sunday, April 29, 2018. (Airbus Defense & Space/38 North/Pleiades CNES/Spot Image via AP)