A U.S. army soldier exercises in front of a M270A1 multiple launch rocket system as they prepare for a live-fire training exercise of the 6-37th Field Artillery Regiment at a training area near the demilitarized zone separating the two Koreas, in Cheorwon, South Korea, March 9, 2016. (Photo by Kim Hong-Ji/Reuters)

Seiichiro Nishimoto, CEO of Shelter Co., poses wearing a gas mask at a model room for the company's nuclear shelters in the basement of his house in Osaka, Japan on April 26, 2017. With nearby North Korea increasing its show of power day by day with missile launches and nuclear tests, people in Japan are preparing for the worst by building private nuclear shelters, Reuters reports. (Photo by Kim Kyung-Hoon/Reuters)

A quake-resistant dome house decorated with Japan's popular “Kumamon” bear character is pictured at the Aso Farm Land resort in Aso, Japan on November 6, 2017. Cabins modelled after Japanese sweets and made from polystyrene foam withstood last year's deadly earthquakes in Kumamoto prefecture. (Photo by Kim Kyung-Hoon/Reuters)

A woman wears VR glasses while the projection mapping is cast on table and walls during its media preview at “TREE BY NAKED, yoyogi park” restaurant in Tokyo, Japan on July 19, 2018. This restaurant incorporates virtual reality, projection mapping, and music to enhance diners' enjoyment of their food. (Photo by Kim Kyung-Hoon/Reuters)

A Ballet dancer prepares backstage during the final dress rehearsal for the famous Nutcracker ballet by Pyotr Tchaikovsky at the Joburg Ballet, Johannesburg, South Africa, 04 October 2018. The premiere of Nutcracker is scheduled for 05 October and the show will run for two weeks. (Photo by Kim Ludbrook/EPA/EFE)

Women in yukatas, or casual summer kimonos, take their selfie in front of paper lanterns during the annual Mitama Festival at the Yasukuni Shrine, where more than 2.4 million war dead are enshrined, in Tokyo, Japan July 13, 2017. (Photo by Kim Kyung-Hoon/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 participate in a mass military parade at Kim Il-Sung square in Pyongyang on October 10, 2015. North Korea was marking the 70th anniversary of its ruling Workers' Party. (Photo by Ed Jones/AFP Photo)