Children wave Vietnamese and American flags while waiting for arrival of U.S. President Barack Obama (not pictured) before a welcoming ceremony at the Presidential Palace in Hanoi, Vietnam May 23, 2016. (Photo by Reuters/Kham)

Kaitlin, 28, from the United States is suspended from hooks pierced through her skin by the professional body artist Dino Helvida in Zagreb, Croatia June 7, 2016. (Photo by Antonio Bronic/Reuters)

Somali government soldiers hold their positions during gunfire after a suicide bomb attack outside Nasahablood hotel in Somalia's capital Mogadishu, June 25, 2016. Somalia's al Shabaab Islamist group launched a suicide bomb attack on a hotel in the center of Mogadishu on Saturday before fighters stormed inside, police and the militant group said. Police said at least 15 people had died, including guards at the site, civilians and militants. Others were wounded. (Photo by Feisal Omar/Reuters)

A view of the scene of a train accident after two commuter trains collided head-on near the town of Andria, in the southern region of Puglia, killing several people, Tuesday, July 12, 2016. (Photo by Luca Turi/ANSA via AP Photo)

A fire engine drives away from flames on the ridge, east of Silverwood Lake in Crestline, Calif., Sunday, August 7, 2016. (Photo by Terry Peirson/The Press-Enterprise via AP Photo)

Chunhun (R), the leader of Japan's North Korea fan club called sengun-joshi, or military-first girls, and other members practice a Moranbong Band dance in Tokyo, Japan on November 2, 2017. (Photo by Toru Hanai/Reuters)

A tufted puffin is seen in Kamchatka Territory, Russia on July 17, 2018. (Photo by Yuri Smityuk/TASS)

Model Heide Lindgren attends Heidi Klum's 12th annual Halloween party at the PH-D Rooftop Lounge at Dream Downtown on October 31, 2011 in New York City. (Photo by Jemal Countess/Getty Images)