Over 180 officials, experts and representatives from China and the United States gathered in Changsha, capital of Central China's Hunan province, to explore cooperation in sustainable energy.

They discussed possible solutions for urban environmental issues such as air pollution, sponge city construction and sewage treatment at the third Sino-US Energy and Environment Forum, themed "Recycling of fugitive gas emission under global concerns on water, air and soil".

Devinder Mahajan, director of the Institute of Gas Innovation and Technology in the United States, said that as two of the largest emitters of greenhouse gases, China and the United States shared common goals and challenges in conserving energy and should tap into each other's strengths.

"The two countries have the same duties and obligations to ensure energy security and cope with environmental challenges," said Zhuang Jia, with China's Ministry of Science and Technology.

Strengthening cooperation in such areas can also help boost economic growth in both countries, he added.

China and the United States signed a 10-year energy and environment cooperation framework in Washington in 2008. The framework sets goals and lays out steps to expand Sino-U.S. cooperation in energy security, environmental sustainability and climate change.

Guided by the framework, over 30 universities in both countries set up the Sino-U.S Energy and Environment Innovation Research Center in 2015. Multiple techniques developed by the center have been successfully applied, according to Chai Xiaoli, head of the center.