Minister Xu Xueyuan of the Chinese Embassy in the United States speaks at a celebration marking the 40th anniversary of sister city relationships between Chinese and U.S. cities in Washington D.C., the United States, on March 13, 2019. (Xinhua/Liu Jie)

WASHINGTON, March 13 (Xinhua) -- The Chinese Embassy in Washington D.C. on Wednesday held a celebration marking the 40th anniversary of sister city relationships between Chinese and U.S. cities.

"Sister cities relationship is a major channel for people-to-people exchanges and sub-national cooperation. It is an important driving force for our relations," Minister Xu Xueyuan of the embassy told the event.

"Sister cities cooperation between China and the U.S. has almost developed in tandem with the overall bilateral ties," Xu said.

"Over the past four decades, the number of sister provinces/states and sister cities between us has grown into 277 pairs. Following the principles of friendship, mutual benefit and practical results, the two sides have made great achievement in their trade and economic cooperation as well as people-to-people ties, with the purpose of common development and shared prosperity," Xu said.

Officials of U.S. states, cities, and towns that have sister city ties with their Chinese counterparts joined the celebration, co-hosted by both the Chinese Embassy and Sister Cities International (SCI), a non-profit organization that promotes local-level ties between the United States and other countries.

The establishment of sister city relationships 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.

The event also celebrated the 40th anniversary of the China-U.S. diplomatic relations, the Chinese embassy said in a statement.