Palestinian President Mahmoud Abbas left here at dawn today wrapping up a four-day visit to the United States during which he met with U.S. President George Bush to discuss the Middle East peace process and efforts made to achieve Bush's vision regarding the establishment of a viable independent Palestinian state. President Abbas addressed the 63rd session of the United Nations General Assembly and also gave a speech before the UN Security Council in which he called on the Council to shoulder responsibility towards the Israeli settlement policy in the Palestinian territories, according to a report of Qatari news agency "QNA".