China and the US are each other's second-largest trading partner. In 2012, the world's two biggest economies saw bilateral trade of $484.7 billion, nearly 200 times what it was when they established diplomatic relations in 1979.
And the two-way investment has been on the rise. By the end of 2012, cumulative US direct investment in China stood at $70 billion, and China's cumulative outbound direct investment in the non-financial sector in the US reached $10 billion.
But US concerns over national security have been a major challenge to Chinese investment in the nation. A report by two members of the US House of Representatives Intelligence Committee in October cited two Chinese telecom equipment firms, Huawei Technologies Co and ZTE Corp, as posing a potential national-security threat to the US.
"Economic cooperation is a very important part of bilateral relations," said Wang Xu, deputy director-general of Department of American & Oceanian Affairs at the Ministry of Commerce.
"Complaints are meaningless. What we can do is nothing but explore possibilities of enhanced cooperation."
As a major part of the drive, Wang said, it is necessary to deepen and advance the cooperation between the Chinese provinces and the US states.
Li Yong, vice-chairman of International Trade Research Institution of China, said: "We have noticed imbalanced bilateral investment relations."
The recent wave of visits to China by US state officials comes just a month after China elected its new leadership, with both the new president and premier vowing to further open up to the outside world.
Xi, who has rich working experience in local governments, has repeatedly stressed the importance of Sino-US provincial and city-level economic exchanges.
As the then vice-president, Xi paid an official visit to the US in early 2012, and the state of Iowa was a key destination of the trip. In 1983, Iowa and Hebei province became sister states, and in 1985, Xi, then a county-level government head in Hebei, visited Iowa for agricultural projects.
On the sidelines of the Second China-US Governors Forum, Iowa Governor Terry Branstad said China and the US are heralding a new starting point for two-way economic and investment relations, while Chinese provinces and the US states vow to be closer.
"We believe that the two sides will build stronger relations," Branstad said.
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