The new U.S. Middle East peace envoy leaves today night on a several country Middle East trip to try to shore up the Gaza ceasefire to promote Israeli-Palestinian peace, Reuters quoted the State Department as saying. George Mitchell, a former U.S. senator and a mediator who helped to resolve the Northern Ireland conflict, was named by Secretary of State Hillary Clinton last week to lead U.S. efforts to end the six-decade Arab-Israeli conflict. State Department spokesman Robert Wood said Mitchell's trip, which will run through Feb. 3, aimed to consolidate the ceasefire that ended Israel's 22-day offensive in the Gaza Strip and to "reinvigorate the peace process." "The administration will actively and aggressively seek a lasting peace between Israel and the Palestinians, as well as Israel and its neighbors," Wood told reporters.