SEATTLE, the United States - A forum kicked off here on Tuesday for US and Chinese cities to discuss how to expand economic cooperation.

The forum, entitled "US-China Initiative on City- Level Economic Cooperation," is an effort to materialize the outcomes of Chinese President Hu Jintao's visit to the United States in January and the second China-US Strategic and Economic Dialogue, said Tu Guangshao, vice mayor of Shanghai and head of the 80-plus Chinese delegation to the forum.

The forum, the first of its kind, will serve as a platform between cities of the two countries to foster their economic partnership, Tu said at the forum's opening.

China's commitment to expanding city-level economic cooperation with the US side is self-evident by the size of the Chinese delegation, which includes officials from the finance, foreign affairs and commerce ministries and metropolises like Shanghai and Chongqing, as well as executives from about 30 Chinese enterprises, Tu noted.

"The US and China have one of the most important bilateral commercial relationships in the world," Rebecca Blank, under secretary for economic affairs of the US Commerce Department, said at the forum on behalf of the Obama administration and the US Department of Commerce.

"We are here to discuss how we can build on this relationship," she said, describing the growth rate in US-China trade in the past decades as "truly amazing."

In 2001, US exports to China were 19 billion, and only nine years later by 2010, the volume totalled nearly 92 billion, she said. China is the US second largest trading partner and its third largest export market.

The United States welcomes the trade growth because it's good for China, for the global economy and for the United States as well, she said.

In January, at least seven separate Chinese delegations toured the United States in conjunction with Hu's visit and more than 500 Chinese government and business leaders visited cities and companies for business cooperation, according to Blank.

"Today's event is a continuation of the US government's efforts to build economic bridges between the US and China," she said.

Beijing and Washington launched the China-US Governors Forum earlier this year for more effective bilateral cooperation.

Blank believed that talks on national or provincial-level will help promote bilateral ties, and city-level talks will have their own role to play as the US and Chinese cities have common problems and challenges and the mayors have a lot to discuss about and can learn from each other.

Some 40 US mayors attended the forum. Many of them expressed interest in the vast Chinese market as well as their willingness to work with their Chinese counterparts to seek mutual development and handle common problems.

At the two-day forum, the two sides will hold round-table dialogues to brief each other on their business environment and investment opportunities, and match-making events will also be held for US and Chinese enterprises to foster partnerships.

A strategic cooperation memorandum was signed between the western Chinese city of Xi'an and its US counterpart Seattle Tuesday on the sidelines of the forum.