A man covered with thermal blanket walks along railway tracks beside an improvised refugee camp on the border line between Macedonia and Serbia near the northern Macedonian village of Tabanovce, Thursday, March 10, 2016. Around 1.500 migrants and refugees are stranded at Tabanovce transit center for refugees in northern Macedonia. (Photo by Boris Grdanoski/AP Photo)

Britain's Prince Harry meets Chewbacca during a visit to the Star Wars film set at Pinewood Studios near Iver Heath, west of London, Britain, April 19, 2016. Prince William and Prince Harry are touring Pinewood to visit the production workshops and meet the creative teams working behind the scenes on the Star Wars films. (Photo by Adrian Dennis/Reuters)

A sales woman of a fish shop shows king crabs to a customer and negotiates the price in Noryangjin Fish Market is seen on August 1, 2015 in Seoul, South Korea. Noryangjin Fish Market was established in 1927 as Gyeongseong Susan in Jung-gu near Seoul Station and moved to its current location in 1971. (Photo by Shin Woong-jae/The Washington Post)

Children guarded by Hungarian police play on the ground after being detained along with other migrants who illegally crossed from Serbia to Hungary near the village of Asotthalom, Hungary, September 16, 2015. (Photo by Dado Ruvic/Reuters)

Workers adjust rails at the bed of a drained area of a lake used for the production of salt at the Sasyk-Sivash lake near the city of Yevpatoria, Crimea, September 25, 2015. The area has a long tradition of salt production, prepared from salt flats flooded with water from the Black Sea. (Photo by Pavel Rebrov/Reuters)

New York Police Department tactical police officers stand guard near the New York Stock Exchange on September 9, 2011 in New York City. Officials are stepping up security in New York and Washington D.C. a day after U.S. officials received a credible but unconfirmed terror threat to utilize car bombs on bridges or tunnels in New York or Washington. (Photo by Justin Sullivan/Getty Images)

A boat paddles behind a fence near a plane sitting on the flooded tarmack of the closed Don Muang airport November 3, 2011 in Bangkok,Thailand. The airport was used as a domestic terminal and was formerly the International airport. Thailand is experiencing the worst flooding in over 50 years and has affected more than nine million people. Over 400 people have died in flood-related incidents since late July according to the Department of Disaster Prevention and Mitigation. (Photo by Paula Bronstein/Getty Images)

Activists stage a protest outside the Louvre pyramid, calling the museum to cancel its contracts with French oil giant Total and Italian oil company Eni, in Paris, France, December 9, 2015, as the World Climate Change Conference 2015 (COP21) continues at Le Bourget near the French capital. (Photo by Benoit Tessier/Reuters)