HOUSTON, July 16 -- Local level cooperation between China and the United States is the driving force of the bilateral relations, Chinese Consul General in Houston Li Qiangmin said Tuesday.

Speaking at a welcoming reception for Chinese delegation to attend the upcoming U.S.-China Sister Cities Mayors' Summit in Houston, Li said the past 40 years have proved that a sound and steady relationship between China and the United States could bring tangible benefits to the two peoples.

Despite twists and turns, "the common interests outweigh differences between the sides," Li continued.

Speaking at the reception, Xie Yuan, vice president of Chinese People's Association for Friendship with Foreign Countries (CPAFFC) said that subnational exchanges between the two counties have flourished and yielded fruitful results in recent years.

"The foundation of China-U.S. relations lies in our people. Friendly exchanges of local government are the main channel and an important way to promote understanding and cooperation between the two peoples," Xie said.

The fourth U.S.-China Sister Cities Mayors' Summit will be held Wednesday in Houston, the fourth largest city in the United States.

Co-sponsored by the CPAFFC and Sister Cities International, the one-day summit features panel discussions, keynote addresses, case studies as well as a multimedia exhibit of more than 300 historic photos to commemorate the 40th anniversary of China-U.S. diplomatic ties.

With the theme of "40 Years Ahead: Stronger Friendship, Closer Cooperation," the summit will bring representatives from around 40 Chinese and U.S. cities together to discuss topics such as innovation and smart cities, maritime silk road, metroplex collaboration and Sino-foreign education exchanges.

Three previous summits were held -- 2014 in Washington D.C., 2015 in Chicago and 2016 in Nanchang, China.

The establishment of sister city relationship between China and the United States started soon after the two countries established their diplomatic ties in 1979, when central China's Hubei Province and the U.S. State of Ohio, and eastern China's Nanjing city and the U.S. city of St. Louis, forged sister relationships.

Forty years on, bilateral sister city relationship has grown and flourished, and now the two countries enjoy 277 pairs of sister relationship at different levels, and the momentum is still going strong.