Thailand pavilion and UAE pavilion. [Gao Erqiang/China Daily]

The fate of many pavilions at Expo remains in the balance. Some may stay, some may be moved to other parts of China, while others will be dismantled and sold. At least one will fall apart naturally.

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Even before the curtain for Expo Shanghai 2010 is raised, Joe H. Villarreal, US commissioner general to the event, has been thinking about the fate of the structure that he and his team scrambled to complete in time.

"We built the facility with the idea in mind that it has a life following Expo. This facility is built to last a thousand years," Villarreal said.

"Given the overarching Expo theme of sustainability, demolishing the building and digging a debris dump is probably not consistent.

"Our hope is that we are able to disassemble and transplant the building and put it to use."

The post-Expo fate of foreign pavilions, especially those costing tens of millions of dollars, has generated strong interest among the public.

According to the rules of the Bureau of International Expositions (BIE), the governing body of the World Expos, and plans from Shanghai Expo organizers, all foreign pavilions are to be dismantled after the event and the Expo site redeveloped.

At the Aichi Expo in Japan five years ago, all the Expo structures were removed and the site was rebuilt as a youth training camp.

After Expo Shanghai, only a few structures will remain on the site. These include the China pavilion, the Theme pavilion, the Cultural Center, Expo Center and Expo Boulevard. These will become permanent landmarks on the site after Expo finishes at the end of October.

But some foreign countries want to retain their pavilions in Shanghai or elsewhere in China as a testament to their friendship with China.

They say the life cycle of materials used in pavilion construction and the Expo theme of sustainable development needs to be considered carefully in determining the fate of these constructions - whether they should be retained, recycled or demolished.

The US pavilion, which raised all its funding ($61 million) through corporate sponsorship and private donations, is the most anticipated foreign pavilion, according to a survey last November by Ogilvy Public Relations Worldwide. The US bans the use of public funds for World Expos.

Although it seems unlikely that the US pavilion will be allowed to remain on the Expo site, Villarreal said he has received expressions of interest from parties would like to have the building moved to their communities.

Finland has taken steps to ensure the fate of its pavilion after Expo. It will be dismantled and sold, a decision made by the country's Ministry of Employment and the Economy during the design stage of the structure.

"The pavilion was designed to last as long as possible. We hope it can stay in China permanently," said Zhou Wei, manager of post-Expo relations for the Finland pavilion.

Designed by leading London-based architects firm Foster and Partners, the sand-colored United Arab Emirates (UAE) pavilion is one of the most eye-catching at Expo.

It will be dismantled and shipped back to the UAE after Expo, said Peter Vine, the Expo team coordinator for UAE.