A woman takes her souvenir picture with a white fox in front of ice sculptures illuminated by coloured lights during the opening day of the 31st Harbin International Ice and Snow Festival in the northern city of Harbin, Heilongjiang province, January 5, 2015. The annual Ice and Snow Festival, organized by China National Tourism Administration and local governments, kicked off on Monday in Harbin, one of the coldest cities in China. (Photo by Kim Kyung-Hoon/Reuters)

Joshua Patino stands on a ladder to put finishing touches on a giant dinosaur exhibit at PAX East in the Boston Convention and Expo Center, Thursday, April 21, 2016, in Boston. PAX East, an annual celebration of gaming culture, is expected to draw tens of thousands of visitors Friday through Sunday. It's a place where serious gamers can preview unreleased video games and devices, compete in tournaments, hear live music and meet others for whom gaming is a way of life. (Photo by Elise Amendola/AP Photo)

South Korea's Black Eagles aerobatics team performs an aerial display forming a Ying and Yang logo during the Singapore Airshow at Changi exhibition center in Singapore on February 16, 2016. (Photo by Roslan Rahman/AFP Photo)

South Korea's Black Eagles aerobatics team perform a maneuver during a preview of the Singapore Airshow at Changi exhibition center in Singapore February 14, 2016. The Airshow will take place from February 16-21. (Photo by Edgar Su/Reuters)

The damaged battleship USS California, listing to port after being hit by Japanese aerial torpedoes and bombs, is seen off Ford Island during the attack on Pearl Harbor, Hawaii, U.S. December 7, 1941. The 75th anniversary of the attack, which brought the United States into World War Two, is marked on December 7, 2016. (Photo by Reuters/U.S. Navy/National Archives)

Soldiers from Japan's Ground Self Defense Force come ashore in amphibious assault vehicle as they train alongside U.S. Marines during the bilateral annual Iron Fist military training exercise in Camp Pendleton, California February 26, 2016. (Photo by Mike Blake/Reuters)

A man walks past an advertisement sign promoting a bank in Seoul in this September 3, 2009 file photo. South Korea is expected to release GDP dara this week. (Photo by Lee Jae-Won/Reuters)

Military helicopters fly in formation above a billboard with a picture of China's late Chairman Mao Zedong during a training session for the upcoming parade marking the 70th anniversary of the end of World War Two, on the outskirts of Beijing, July 2, 2015. Troops from Russia and Mongolia will march together with Chinese forces in a parade in Beijing in September to commemorate the end of World War Two, the government and state media said on Thursday, confirming the first two foreign participants. (Photo by Jason Lee/Reuters)