Polish President Bronislaw Komorowski holds a copy of U.S. President Barack Obama's letter, as he leaves a press conference in Warsaw, Poland, Friday, June 1, 2012. Obama has written a letter to Komorowski expressing "regret" for an inadvertent verbal gaffe that caused a storm controversy in Poland this week, after the U.S. President used the expression "Polish death camp" , rather than "Nazi death camp in German occupied Poland, while honoring a Polish WW II hero. (AP Photo/Alik Keplicz)