Organizers of the 2010 World Expo in Shanghai said Sunday they were confident the United States would overcome funding problems to take part and appealed to President Barack Obama for his support.

U.S. organizers have been struggling to raise the $61 million needed for a pavilion at the event — a problem compounded because American law prohibits government funding of such events, which must instead be privately financed.

"We are confident that this problem will be resolved sooner or later," Wan Jifei, the deputy director of the organizing committee, told a news conferenceChina's annual legislative session. on the sidelines of China's annual legislative session.

"We are following the situation closely and hope that the Obama administration will also pay attention and attach importance to this World Expo and help to resolve these problems," Wan said.

The Expo is an important event for Shanghai, China's business capital, presenting an opportunity to overhaul and showcase the city. China would likely see a U.S. absence as a slap in the face — and a massive missed business opportunity. A record 70 million visitors are expected.

"We hope the U.S. can participate in the Expo so that it can display its image, expand its influence and strengthen its exchange and cooperation with other countries," Wan said. "At the same time, it will give the 1.3 billion Chinese people an opportunity to have a better and in-depth understanding of the United States."

Wan said the U.S. has confirmed its participation verbally but not with a written commitment, which is needed by mid-April, Expo organizers say.

The U.S. missed the 2000 Expo in Hanover, Germany, because of a lack of funding. The U.S. pavilion at the 2005 Expo in Aichi, Japan, was built with help from Japanese companies, including Toyota Motor North America.

The Shanghai Expo will open May 2010 to October 2010. City authorities plan to break ground at the Expo site — a 2-square mile (5.3-square kilometer) swath of former shipyards, steel mills and riverside slums — on April 30 this year.