U.S President Donald Trump, center, participates in a group photo prior to the Three Seas Initiative transatlantic roundtable in the Great Assembly Hall of the Royal Castle, in Warsaw, Thursday July 6, 2017. The Three Seas Initiative is an alliance among a dozen eastern and central European nations that are bordered by the Adriatic, Baltic and Black seas. The group aims to reduce their dependence on oil and gas supplied by Russia. (AP Photo/Evan Vucci)