Grand Isle Mayor David Camardelle (L) points out areas on a map during a briefing with US President Barack Obama at the US Coast Guard Station in Grand Isle, Louisiana, in this White House handout photo taken on May 28, 2010 and released on June 7, 2010. Picture taken May 28, 2010. Obama sought to reassure Americans on Monday that the Gulf of Mexico oil spill will be stopped, even as he warned that the economic impacts of the disaster would be substantial and ongoing.[Agencies]