A Syrian youth Khaled from Raqqa walks on snow wearing slippers in the Bekaa Valley refugee camp in Lebanon after the first heavy snow storm hit Lebanon, January 3, 2016. (Photo by Jamal Saidi/Reuters)

Green Bay Packers' Johnathan Calvin rides a bike to NFL football training camp on July 27, 2017, in Green Bay, Wis. (Photo by Morry Gash/AP Photo)

Rohingya refugee sisters Nur Kaida (R) and Ruhana hug each other at their shelter at the Palongkhali refugee camp near Cox's Bazar, Bangladesh December 21, 2017. (Photo by Marko Djurica/Reuters)

Iraqi security forces take part in training, as they prepare to fight against militants of the Islamic State, at a training camp on the outskirts of Mosul January 10, 2015. (Photo by Azad Lashkari/Reuters)

A pro-democracy demonstrator fights with a Soviet soldier on top of a tank parked in front of the Russian Federation building on August 19, 1991, after a coup toppled Soviet President Mikhail Gorbachev. The same day, thousands in Moscow, Leningrad, and other cities answered Russian Republic President Boris Yeltsin's call to raise barricades against tanks and troops. (Dima Tanin/AFP/Getty Images)

A woman reacts while walking among the ruins of damaged buildings following heavy fighting between government troops and Kurdish fighters, on March 2, 2016 in the southeastern Turkey Kurdish town of Cizre, near the border with Syria and Iraq. Thousands in Turkey's Kurdish-majority town of Cizre started returning to their homes today after authorities partially lifted a curfew in place since December for a controversial military operation to root out separatist rebels. (Photo by Yasin Akgül/AFP Photo)

Cars pass a tank position close to the Russian border near the Ukrainian city of Kharkiv March 24, 2014. U.S. President Barack Obama sought support from European allies and China on Monday to isolate Russia over its seizure of Crimea, and Ukraine told its remaining troops to leave the region after Russian forces overran one of Kiev's last bases there. (Photo by Dmitry Neymyrok/Reuters)