U.S. soldiers wrestle with South Korean soldiers in a muddy ring during a joint ranger training exercise at a ranger camp near the demilitarised zone (DMZ) June 25 2003 in Paju, South Korea. (Photo by Chung Sung-Jun/Getty Images)

South Korean divers prepare to plunge through a hole in the ice of the frozen Imjin River on January 16, 2005 in Yeonchun, South Korea. (Photo by Chung Sung-Jun/Getty Images)

Members of the South Korean Special Weapons and Tactics team exhibit their skill during anti-terrorism exercises at a training camp on May 30, 2005 in Seoul, South Korea. (Photo by Chung Sung Jun/Getty Images)

A student attending a winter military camp reacts during a training session in Ansan, south of Seoul January 3, 2013. Hundreds of students between 11 and 17 years old attend winter boot camp training courses every year. The winter courses range from 4 to 14 days at the Blue Dragon Camp run by retired marines, which also offers summer boot camp for students. (Photo by Kim Hong-Ji/Reuters)

15-year old American girl Donica Streling meets with members of SHINee (샤이니) at SM Entertainment head office on June 20, 2012 in Seoul, South Korea. Donica, diagnosed with Charcot-Marie-Tooth disease, visited Seoul, South Korea to meet her favorite K-pop groups SHINee and Super Junior after finding hope in listening to Korean pop. (Photo by Chung Sung-Jun)

A woman stands in a gift shop in central Rason city, part of the special economic zone northeast of Pyongyang, in this August 30, 2011 file photo. North Korea is a militarized, male-dominated society, but it is women who are making the money as the insular nation allows an unofficial market-based economy to take shape. (Photo by Carlos Barria/Reuters)

A traffic police woman whistles at a pedestrian, Monday, July 27, 2015, in Pyongyang, North Korea where its citizens are having a one-day national holiday to celebrate the country's 62nd anniversary of the armistice that ended the Korean War. (Photo by Wong Maye-E/AP Photo)