Ukrainian servicemen patrol near the humanitarian aid center in Avdiivka, Ukraine, Saturday, February 4, 2017. Fighting in eastern Ukraine sharply escalated this week. Ukraine's military said several soldiers were killed over the past day in shelling in eastern Ukraine, where fighting has escalated over the past week. (Photo by Evgeniy Maloletka/AP Photo)

Russian servicewomen march at Red Square during the Victory Day military parade in Moscow on May 9, 2017. Russia marks the 72nd anniversary of the Soviet Union's victory over Nazi Germany in World War Two. (Photo by Kirill Kudryavtsev/AFP Photo)

Italian Air Force's aerobatic demonstration team, the Frecce Tricolori leave colourful vapour trails as they fly over the Altare della Patria monument on Republic Day (Festa della Repubblica) in Rome, Italy, 02 Jun 2017. The anniversary marks the founding of the Italian Republic in 1946. (Photo by Massimo Percossi/EPA)

In this photo provided by Tasnim News Agency, relatives weep over the body of an earthquake victim, in Sarpol-e-Zahab, western Iran, Monday, November 13, 2017. An earthquake measuring 7.3 on the Richter scale rocked northern Iraq and Iran, the U.S. Geological Survey said on Sunday evening. Photo by Farzad Menati/Tasnim News Agency via AP Photo)

Residents cross over an improvised bridge after a landslide sent mud and water crashing onto homes close to the municipality of Salgar in Antioquia department, Colombia May 19, 2015. A landslide sent mud and water crashing onto homes in a town in Colombia's northwest mountains on Monday, killing at least 50 people and injuring dozens, officials said. (Photo by Jose Miguel Gomez/Reuters)

In this photo provided by Mickey Nuttall, members of an international team of skydivers join hands, flying head-down to build their world record skydiving formation, Friday, July 31, 2015, over Ottawa, Ill. (Photo by Jason Peters via AP Photo)

Barny, the Harveys Brewery dog has a sniff of a pint of beer at the Great British Beer Festival, at Olympia in London, Tuesday, August 11, 2015. The five day event is organised by the Campaign for Real Ale (CAMRA), with over 900 real ales, ciders, perries and international beers on offer. (Photo by Kirsty Wigglesworth/AP Photo)

In this Wednesday, July 13, 2016, handout image provided by Solar Impulse, the Solar Impulse 2 flying over the pyramids, Egypt Cairo. The experimental solar-powered airplane has arrived in Egypt as part of its global voyage. (Photo by Jean Revillard, Rezo via the AP Photo)