North Korean leader Kim Jong Un is hugged by children during his visit to Samjiyon County in this undated photo released by North Korea's Korean Central News Agency (KCNA) in Pyongyang November 28, 2016. (Photo by Reuters/KCNA)

Kayaks, 7, poses for a picture holding toy gun in a camp where Christians displaced by Islamic State militants are living, in Irbil, Iraq, Friday, December 23, 2016. Iraq’s Christians are marking the holiday in his camp for displaced people with a sense of worry and despair, unable to return to their towns they were forced to flee two years ago by the Islamic State group’s onslaught. (Photo by Manu Brabo/AP Photo)

Roof-topping enthusiast Daniel Lau takes a selfie with high-rise buildings down below as he stands on the top of a skyscraper in Hong Kong, China on August 15, 2017. A craze that began in Russia has now taken hold in Hong Kong, one of the world's most vertical cities. Mr Lau said he had been inspired by Russian climbers and that he was unafraid of the vertiginous heights he scales. (Photo by ImagineChina/Rex Features/Shutterstock)

A performer poses during celebrations after Rahul Gandhi, newly elected president of India's main opposition Congress party, took charge as the president during a ceremony outside the party's headquarters in New Delhi, India, December 16, 2017. (Photo by Altaf Hussain/Reuters)

Hundreds of hardy swimmers across Britain braved jumping into freezing cold waters for a annual Christmas Day dip on December 25, 2017. (Photo by Dave Nelson/The Sun)

A SpaceX Falcon Heavy rocket lifts off from historic launch pad 39-A at the Kennedy Space Center in Cape Canaveral, Florida, February 6, 2018. The world' s most powerful rocket, SpaceX' s Falcon Heavy, blasted off Tuesday on its highly anticipated maiden test flight, carrying CEO Elon Musk' s cherry red Tesla roadster to an orbit near Mars. Screams and cheers erupted at Cape Canaveral, Florida as the massive rocket fired its 27 engines and rumbled into the blue sky over the same NASA launchpad that served as a base for the US missions to Moon four decades ago. (Photo by Thom Baur/Reuters)

North Korean leader Kim Jong Un, his wife Ri Sol Ju and Song Tao, head of the International Department of Communist Party of China (CPC) Central Committee, applaud with ballet dancers in this undated photo released by North Korea's Korean Central News Agency (KCNA) in Pyongyang April 17, 2018. (Photo by Reuters/KCNA)

A man plays with his pet goat while taking a bath to cool off in a canal during hot and humid weather in Lahore, Pakistan May 30, 2018. (Photo by Mohsin Raza/Reuters)