HOUSTON, July 18 -- People-to-people exchanges have contributed to the development of China-U.S. relations in the past decades as the exchanges serve to consolidate the foundation of bilateral ties, a leader of a U.S.-China exchange organization has said.

The development of China-U.S. relations began with the people, and from "Ping-pong diplomacy" to increasingly close economic and trade exchanges at the local level, these activities have laid the foundation for a healthy and stable development, Fan Bo, president of U.S.-China Partnerships, told Xinhua in an interview at the fourth U.S.-China Sister Cities Mayors' Summit held in Houston on Wednesday.

The U.S.-China Partnerships is a non-profit organization established in 2014, which is intended to promote mutual understanding and cooperation between the United States and China.

"The association between the people and the cities is at the core of the China-U.S. relations," said Fan, who also represents China at Sister Cities International (SCI) Foundation.

In his eyes, the Sister Cities Mayors' Summit is significant to boosting friendly relations between the United States and China.

"Through the summit, people from both China and the United States have reviewed the friendship between the cities and the peoples in the past. We realized where this friendship comes from and how important it is," Fan said.

For the two countries, city sisterhood started soon after they established diplomatic ties in 1979, from the twinning of the Chinese province of Hubei and the U.S. State of Ohio, and of the Chinese city of Nanjing and the U.S. city of St. Louis, according to Fan.

Fan said many stories were told of the friendly exchanges at the local level. For example, he said, "Some American friends donated wheelchairs to disabled Chinese. The Martin Luther King Jr. Memorial in Washington D.C. is a creation by a Chinese sculptor."

In the past decades, bilateral cultural and people-to-people exchanges have grown and flourished, bringing the two peoples closer, boosting the local development on both sides and renewing the vitality of U.S.-China ties, said Fan.

"I felt there has been a very solid relationship between Chinese and American people through these activities," he added.

"Even though some twists and turns are inevitable in bilateral relations, the general direction has been being friendly at the local level," he said, adding "I think everyone should see the trend and the bright side because many problems may be solved on this basis."

Co-sponsored by the Chinese People's Association for Friendship with Foreign Countries and the SCI, the U.S.-China Sister Cities Mayors' Summit this year featured panel discussions, keynote addresses, case studies as well as a multimedia exhibit of more than 300 historical photos to mark the 40th anniversary of China-U.S. diplomatic ties.

The previous three editions of the summit were held in Washington D.C. in 2014, in Chicago in 2015 and in Nanchang, capital city of the southeastern Chinese province of Jiangxi, in 2016.