* Trip to signal hope Haiti still "winnable" * Senate elections, Washington donor conference next month By Patrick Worsnip PORT-AU-PRINCE, March 9 (Reuters) - U.N. Secretary-General Ban Ki-moon arrived in Haiti on Monday, along with former U.S. President Bill Clinton, on a brief visit to work on an "action plan" to tackle the grinding poverty in the Caribbean state. Ban was to meet later in the day with President Rene Preval to discuss the plan to revive the poorest nation in the Western Hemisphere, long afflicted by political instability and violence and heavily damaged by hurricanes last year. According to the United Nations, which has some 9,000 peacekeepers in Haiti, the plan focuses on job creation, food security, reforestation of the almost treeless country and provision of basic services such as healthcare. Ban told reporters aboard his plane that his visit was to "show solidarity with Haiti's people" and to "create a good political atmosphere". He added: "I urge Haiti's people to seize this opportunity." A U.N. statement said Ban had asked Clinton to accompany him because of his attention to Haiti during his 1993-2001 presidency and a "call to action" on Haiti at a session of his Clinton Global Initiative foundation last September. "The presence of the Secretary-General and President Clinton will bring a strong message of hope that Haiti is still 'winnable,'" the statement said, adding that new partnerships were needed to rebuild the country after the storm damage. The hurricanes in August and September were estimated to have killed some 800 people and caused $1 billion worth of damage. The United Nations launched an appeal last September for $108 million for hurricane relief, but less than half of that had been pledged as of December. However, a high-level donor conference is scheduled for next month in Washington. Ban has stressed the need for political reconciliation and human rights improvements in Haiti. His visit comes just over a month before Senate elections, already controversial after the nation's biggest party, associated with exiled former President Jean-Bertrand Aristide, was barred on a technicality. Immediately after Ban's visit, the U.N. Security Council will stage a three-day trip of its own to assess progress in Haiti and how the U.N. mission is fulfilling its mandate. The trip was originally planned for last September but was postponed because of the hurricanes. (Editing by Eric Walsh)