Locke said he hoped the 27 US energy and railway companies in the delegation can help Xinjiang achieve sustainable energy development.

Christopher Smith, deputy assistant secretary for oil and natural gas in the Office of Fossil Energy at the US Department of Energy, said that in the US, coal fuels about 40 percent of electricity production and will remain an important mix for both countries.

But at the same time, they must work together to develop technologies to reduce carbon dioxide and other emissions.

Xinjiang relies on its rail network, which brings opportunities for US transportation companies like GE Transportation, said Yang Xie, general manager for Greater China.

Xinjiang has more than 4,300 kilometers of railways and its target is to reach 10,000 km by 2015. The region's potential is huge both for international companies and domestic companies, he said.

Yang said although the US is an expert in freight rail networks, its passenger services are not as developed as China's. As a result, the two countries have much to learn from each other.