The United States and Mexico have a close and complex bilateral relationship, with extensive economic linkages as neighbors and partners under the North American Free Trade Agreement (NAFTA). In recent years, security issues have dominated U.S.-Mexican relations, as the United States has supported Mexican President Felipe Calderón's campaign against drug trafficking organizations (DTOs) through bilateral security cooperation initiatives including the Mérida Initiative, an anti-crime and counterdrug assistance package first funded in FY2008.