2日从上海世博会事务协调局了解到，目前，上海世博会组织者尚在等待美国政府正式确认参展中国2010年上海世界博览会（简称上海世博会）以及任命展区总代表的正式函件。 我要收藏 上海世博局相关负责人强调，根据国际展览局有关规定，世博会组织者只有收到受邀参展方的正式确认参展照会，方可认定其为正式参展。 World Expo organizers said on Thursday that the official US confirmation for its participation at the 2010 World Expo Shanghai had not been received. The US government’s recent appointment of a commissioner general for the 2010 World Expo and remarks by Secretary of State Hillary Clinton strongly indicated that the country would attend the 2010 event. Participation of the event requires an official confirmation, officials with the Bureau of Shanghai World Expo Coordination said. The US State Department on Wednesday appointed Jose Villarreal, an attorney from San Antonio, Texas, to head America’s Expo participation and oversee the construction of the US Pavilion. The US hopes to build a 5,600-square-meter pavilion, one of the largest at the Shanghai event.