Both China and the United States stand to gain from cooperation and lose from confrontation, and cooperation is the only right option, Chinese Ambassador to the United States Cui Tiankai said in a congratulatory letter to the 2019 China-California Business Forum.

In the letter read at opening ceremony of the annual forum, Cui said the forum "fully demonstrates the strong expectations of sub-national governments, enterprises and people of both countries on the sound development of their relations."

The ambassador noted that California has been deeply involved in close cooperation with China in fields of trade, investment, tourism, education and others, benefits from China-US economic and trade relations.

Cui mentioned that this year marks the 40th anniversary of the establishment of China-US diplomatic relations. Bilateral relations have developed with the dedication and contribution of generations of people and deserve to be cherished by the two sides.

"The Chinese government and people will stay committed to advancing China-US relations based on coordination, cooperation and stability," Cui said in the letter.

China is California's largest trading partner and the third largest export destination for goods, according to the Chinese Consulate General in Los Angeles. Among the US states, California has attracted the most Chinese investment and tourists and has the biggest number of international students from China.