ANNAPOLIS, United States, July 18 (Xinhua) -- The U.S. state of Maryland and China's eastern province of Anhui celebrated the 31st anniversary of their sister state relationship in Annapolis Monday.

Wang Sanyun, governor of Anhui Province, led a 50-member delegation to attend the ceremony hosted by Maryland Governor Martin O'Malley at the governor's mansion in the state capital Annapolis.

"Over the past 31 years, we have already signed a total of five package agreements, and expanded our educational, cultural, economic and trade cooperation," said Wang, who also met with his Maryland counterpart during the first China-U.S. Governors Forum held in Salt Lake City Friday.

O'Malley said his state's relationship with Anhui is the most long-lasting and valuable partnership Maryland has ever had, and the exchanges and cooperation between the two sides, based on mutual respect and benefit, have been very fruitful.

He announced that July 18 would be Anhui Day in Maryland, reflecting the increasingly close relationship between the two sides.

Wang and O'Malley also signed a joint statement on intensifying strategic cooperation between Maryland and Anhui, and inked a number of economic contracts and agreements worth 1.54 billion U.S. dollars.