The United Nations has high hopes that the Shanghai Declaration will become a "useful roadmap" for tackling climate change and other environmental, urban and social issues, Awni Behnam, assistant secretary-general of the UN, said over the weekend.

The declaration, the key document of Expo 2010 Shanghai, aims to set a new milestone in the history of World Expos by issuing a set of proposals for using clean energy, an area in which China is emerging as a world leader, building greener communities and dealing with aging populations, among other issues.

"This has been a serious Expo, an Expo that has touched on this important theme," Behnam said.

"The declaration will give us a useful roadmap for dealing with climate change and many other pressing issues It has a moral value that depends on the political goodwill of its signatories to implement it."

The declaration, which is being closely supervised by the UN and the Bureau of Shanghai World Expo Coordination, aims to summarize six months of forums and discussions featuring input from the Expo's 246 participating countries, regions and international organizations.

It will be released when the Expo ends on Oct 31, just weeks before the UN's climate talks resume in Cancun in December after last year's meeting in Copenhagen ended in a frustrating stalemate.

Organizers of the document hope it will serve as a stepping-stone toward constructive policy making forged in the spirit of goodwill and collaborative effort, which have become hallmarks of the World Expo.

"We have to get a hold of climate change, lower our carbon emissions, stop our destruction of the seas and learn to live in a sustainable fashion with and from the resources at our disposal," said Behnam.

Behnam, who as commissioner-general of the UN Pavilion placed a statue of a polar bear outside its gates to press home the importance of conserving the environment, said China was leading the charge to build a greener economy.

"I believe there's a commitment from China (to new energy) that's remarkable. It's doing a lot more than other nations in this field," he said.

Last year China emerged as the world's biggest spender on new energy, a trend that looks set to continue this year as policymakers map out electric bus networks in Shanghai, and use the Expo as a test ground for the commercialization of vehicles powered by fuel cell.

Such moves are welcomed by the 44 UN agencies operating for the first time under one roof at a World Expo in Shanghai. Some 35 percent of them address problems related to climate change.

The UN Pavilion welcomed its 1.5 millionth visitor last week.