Barack Obama in Germany

President Barack Obama arrives in Dresden, Germany on Thursday (4 June) Photograph: Gerald Herbert/AP

Obama walks towards a car at the airport in Dresden Photograph: Miguel Villagran/Getty Images

Obama eats a snack in his limousine after he steps off Air Force One Photograph: Fabrizio Bensch/Reuters

German police keep watch from the roof of a hotel across from Dresden castle before the arrival of the US president and German chancellor Angela Merkel on Friday (5 June) Photograph: Mandel Ngan/AFP/Getty Images

Obama walks towards the Gruenes Gewoelbe (Green Vault) in Dresden Photograph: Miguel Villagran/Getty Images

Merkel and Obama sign the golden book in the Gruenes Gewoelbe Photograph: Miguel Villagran/Getty Images

Obama speaks at a joint press conference with Merkel at Dresden castle Photograph: Mandel Ngan/AFP/Getty Images

Obama tours the former Buchenwald Nazi concentration camp with Holocaust survivor Elie Wiesel and Merkel in Buchenwald, Germany. Obama's great-uncle, Charles Payne, was among the first US soldiers to arrive at the nearby subcamp of Ohrdruf in 1945 Photograph: Gerald Herbert/AP

Obama, Merkel with Wiesel, right, and International Buchenwald Committee president, Bertrand Herz, left, at Buchenwald concentration camp Photograph: Sean Gallup/Getty Images

Obama and Merkel listening to Wiesel and Herz, also a Holocaust survivor Photograph: Kai Pfaffenbach/AP

Obama pays his respects at a memorial plaque in front of the gate building at the Buchenwald concentration camp Photograph: Oliver Multhaup/Reuters

Four white roses put down by Obama, Merkel and Buchenwald survivors Wiesel and Herz on a commemoration plate at the concentration camp Photograph: Oliver Multhaup/AP