Radek Sikorski, a former Polish foreign ministers, speaks to The Associated Press in Warsaw, Poland, on Monday May 16, 2016. Sikorski, who has strong ties to Britain and has been advocating for Britain to remain in the European Union, said he is "very worried" about the prospect of so-called Brexit. He said he fears it could weaken a political arrangement that has given Europe's its longest-ever period of peace and prosperity. (AP Photo/Czarek Sokolowski)