Prime Minister Theresa May meets Russian President Vladimir Putin during the G20 summit in Osaka, Japan on June 28, 2019. (Photo by Stefan Rousseau/PA Images via Getty Images)

North Koreans perform during a mass game of “The Land of the People” at the May Day Stadium in Pyongyang, North Korea, Tuesday, June 25, 2019. (Photo by Jon Chol Jin/AP Photo)

A hot air balloon competition called “Grudziadzkie Zawody Balonowe” is held in Lisie Katy, central-northern Poland, 14 May 2021. The compe​tition is held for the eighteenth time. (Photo by Tytus Zmijewski/EPA/EFE)

Chantel Jeffries arrives for the opening ceremony and screening of the film “Everybody Knows” on May 8, 2018 during the 71st annual Cannes Film Festival in Cannes, France. (Photo by Eric Gaillard/Reuters)

Long row of shiny new Flying Fortresses, part of huge reserves being built up in Britain for D-Day, stands by to be flown to combat units as replacements, May 25, 1944. (Photo by AP Photo)

A riot policeman fires into the air during clashes with opposition supporters at a rally demanding a referendum to remove President Nicolas Maduro in Caracas, Venezuela, May 11, 2016. (Photo by Carlos Garcia Rawlins/Reuters)

A pilgrim walks on her knees to fulfil her vows, as pilgrims attend the 99th anniversary of the appearance of the Virgin Mary to three shepherd children, at the Catholic shrine of Fatima, Portugal May 12, 2016. (Photo by Rafael Marchante/Reuters)

Women carry a portable shrine, a Mikoshi, through a street in Tokyo's Asakusa district during the Sanja festival, Japan, May 15, 2016. (Photo by Thomas Peter/Reuters)