HOUSTON, May 18 (Xinhua) -- Local-level collaboration and exchanges are still strong despite the ongoing U.S.-China trade tensions, experts have said here at the just concluded fourth U.S.-China Innovation and Investment Summit.

"They (cities, companies and individuals on both sides) work together every day in ways that you don't see headlines about and that we often forget about," said David Firestein, founding executive director of the China Public Policy Center.

People-to-people and business-to-business exchanges are the basis of U.S.-China relations, said the expert, also CEO of the George H. W. Bush Foundation for U.S.-China Relations.

Similarly, Chinese Consul General in Houston Li Qiangmin said that the "development of communication on city and local level is of special significance."

The cooperation between China and the United States is unstoppable despite their trade frictions, and the need for innovation remains strong, said Li, adding that the summit has built a bridge for small businesses in the two countries.

The event is "setting up a platform between enterprises in China and the United States, especially for those small and medium-sized ones," Li said, adding that the event has expanded significantly since its first launch in 2016 and that it is attracting more companies and scientific research institutions.

Jointly hosted by the China Science & Technology Exchange Center and U.S.-China Innovation Alliance, the two-day summit kicked off on Thursday and attracted around 300 participants from China and the United States, including entrepreneurs and investors.