US President Barack Obama said Easter and Passover presented an opportunity for reflection on turmoil around the world. "Earlier this week, Jewish people gathered with family and friends to recite the stories of their ancestors' struggle and ultimate liberation," Obama said in his weekly radio address on Saturday, two days after he hosted a White House presidential seder. "Tomorrow, Christians of all denominations will come together to rejoice and remember the resurrection of Jesus Christ. The holidays are "very different," the president said, "but it seems fitting that we mark them both during the same week. For in a larger sense, they are both moments of reflection and renewal." Obama called for reflection on the obligations Americans have to themselves and to others, noting the economic crisis, the spread of disease, the proliferation of weapons, the increase in terrorism and efforts to develop cleaner energy sources. "It is only by building a new foundation of mutual trust that we will tackle some of our most entrenched problems," he said. "That is why, in Turkey, I spoke to members of Parliament and university students about rising above the barriers of race, region and religion that too often divide us."