North Korean defectors, now living in South Korea, prepare to release balloons carrying propaganda leaflets denouncing North Korea's late leader Kim Jong-Il at Imjingak, near the Demilitarized zone (DMZ) separating South and North Korea on December 28, 2011 in Paju, South Korea. (Photo by Chung Sung-Jun/Getty Images)

An Iranian soldier guards two German tourists near the Iranian-Turkish border during World War II. Since the British occupation of Iran, all Axis nationals are being expelled from the country. (Photo by Three Lions/Getty Images). Circa 1941

North Korean cheerleaders arrive at a rest stop, or service station, as their bus convoy carrying a 280- member delegation on its way to the 2018 Pyeongchang winter Olympic games, makes its way past Gapyeong on February 7, 2018 More than 200 young North Korean women arrived in South Korea to root for athletes from both sides of the peninsula at the Winter Olympics. (Photo by Ed Jones/AFP Photo)

A soldier stands guard on the aircraft park of the Pyongyang Airport on April 3, 2011 in Pyongyang, North Korea. Pyongyang is the capital city of North Korea and the population is about 2,500,000.

Migrants wait to cross the Slovenia-Austria border in Sentilj, Slovenia, October 27, 2015. The first five border guards – all German – of 400 promised to Slovenia by fellow EU countries are expected to arrive on Wednesday to help channel a huge flow of migrants through the tiny Alpine state, its government said. Interior Ministry state secretary Bostjan Sefic also said 100-120 customs police would join Slovenian soldiers, regular police and private security firms in dealing with an influx that has strapped the country's limited resources. (Photo by Srdjan Zivulovic/Reuters)

North Korean women soldiers take part in a military parade Saturday, April 15, 2017, in Pyongyang, North Korea, to celebrate the 105th birth anniversary of Kim Il Sung, the country's late founder and grandfather of current ruler Kim Jong Un. (Photo by Wong Maye-E/AP Photo)

A woman is supported by two men while crossing a river, north of Idomeni, Greece, as migrants attempt to reach Macedonia on a route that would bypass the border fence, Monday, March 14, 2016. Hundreds of migrants and refugees walked out of an overcrowded camp on the Greek-Macedonian border Monday, determined to use a dangerous crossing to head north. (Photo by Vadim Ghirda/AP Photo)

An immigrant from Mali rests at the Greek-Macedonian border before an attempt to flee to Macedonia May 13, 2015 village of Idomeni in Kilkis prefecture May 13, 2015. Hundreds of mostly Afghan, Syrian, and African immigrants cross daily from Greece into Macedonia on their way to northern European countries; most of them are turned back by Macedonian border guards. (Photo by Yannis Behrakis/Reuters)