In this Friday, August. 17, 2018, photo, a North Korean waitress prepares to serve dinner to Chinese tourists at the Pegaebong hotel in Samjiyong in North Korea. Chinese businesspeople and tourists are once again flowing over the borders – several large tourist groups were in Samjiyon last week – and South Korean officials are seriously considering ways to help the North improve its roads and railways. (Photo by Ng Han Guan/AP Photo)

A member of North Korean military holds flowers to be laid at the bronze statues of the late leaders Kim Il Sung and Kim Jong Il at Mansu Hill Grand Monument in Pyongyang, North Korea, Monday, December 17, 2018. North Koreans are marking the seventh anniversary of the death of leader Kim Jong Il with visits to the statues and vows of loyalty to his son, Kim Jong Un. (Photo by Dita Alangkara/AP Photo)

Two railway workers chat in front of a flower mural inside a subway station visited by foreign reporters during a government organised tour in Pyongyang, North Korea October 9, 2015. (Photo by Damir Sagolj/Reuters)

Soldiers pose for a photo during the flower exhibition marking the 105th birth anniversary of the country's founding father, Kim Il Sung in Pyongyang, North Korea April 16, 2017. (Photo by Damir Sagolj/Reuters)

A soldier eats ice cream as she visits a zoo in Pyongyang, North Korea, September 12, 2018. (Photo by Danish Siddiqui/Reuters)

A subway worker walks away after a train departed the station in central Pyongyang, North Korea May 7, 2016. (Photo by Damir Sagolj/Reuters)

A picture released by the North Korean Central News Agency (KCNA) shows Kim Jong-un convening an urgent operation meeting at 0:30 am on March 29, 2013 at an undisclosed location, in which he ordered strategic rocket forces to be on standby to strike US and South Korean targets at any time. (Photo by KCNA via EPA)

North Korean soldiers look at South Korea across the Korean Demilitarized Zone (DMZ), on December 22, 2011 in Panmunjom, South Korea. (Photo by Chung Sung-Jun/Getty Images)