Barack Obama on Friday called on Arab states to show willingness to set up diplomatic and commercial ties with Israel in return for “tough commitments” from the Jewish state as he reinforced his determination to launch a fresh drive to broker Middle East peace.

His statement came ahead of a poignant visit to the Buchenwald former concentration camp in Germany, on a day that saw Mr Obama try to assuage concerns – both in Israel and at home – about the direction of his Middle East policy.