A worker cleans the floor of the Grotto, where Christians believe the Virgin Mary gave birth to Jesus, at the Church of the Nativity ahead of U.S. President Barack Obama's visit to the church in the West Bank town of Bethlehem March 20, 2013. Obama arrived in Israel on Wednesday without any new peace initiative to offer disillusioned Palestinians and facing deep Israeli doubts over his pledge to prevent a nuclear-armed Iran. REUTERS/Ammar Awad (WEST BANK - Tags: POLITICS RELIGION)