South Korean rescue members wearing chemical protective suits walk past a monster character (R) during an anti-terror drill as part of a disaster management exercise at the COEX shopping and exhibition center in Seoul on May 20, 2016. South Korea is holding its 2016 Safe Korea anti-disaster exercise this week against terrorist threats and natural disasters. (Photo by Jung Yeon-Je/AFP Photo)

North Korean leader Kim Jong Un (3rd R) and wife Ri Sol Ju (4th L) enjoy an art performance given by the Chongbong Band to mark the 70th anniversary of the founding of the Workers' Party of Korea (WPK) in this undated photo released by North Korea's Korean Central News Agency (KCNA) in Pyongyang on October 19, 2015. (Photo by Reuters/KCNA)

Performers of Everland Amusement Park present the part of Christmas Fantasy in downtown of Myundong in Seoul, South Korea on December 3, 2019. (Photo by Seokyong Lee/Penta Press/Rex Features/Shutterstock)

Participants play with water guns during the Sinchon Water Gun Festival in Seoul, South Korea, July 9, 2016. (Photo by Kim Hong-Ji/Reuters)

South Korean special warfare command soldiers participate in winter military training exercise on January 11, 2012 in Pyeongchang-gun, South Korea. The South Korean troops train in temperatures below -20 degrees celsius to defend the country against any possible attacks from North Korea. (Photo by Chung Sung-Jun/Getty Images)

Fireworks illuminate the sky over downtown Seoul during the International fireworks festival 2007 at Han River on October 13, 2007 in Seoul, South Korea. The United States, Japan and South Korea have team was attending the festival. (Photo by Chung Sung-Jun/Getty Images)

North Korean traffic police women chat next to a residential building while off duty Tuesday, October 18, 2016, in Pyongyang, North Korea. (Photo by Wong Maye-E/AP Photo)

A traffic police officer directs vehicles at a street junction during sunset in Pyongyang, North Korea, Thursday, August 25, 2016. (Photo by Dita Alangkara/AP Photo)