To strengthen positive relations between the two countries and their two navies, the People’s Republic of China and the United States have conducted a series of exchange visits over the past 14 years. The focus has been in the Pacific, where the North Sea Fleet of the People’s Liberation Army-Navy (PLA-N) and the Seventh Fleet of the U.S. Pacific Fleet have visited each other’s main naval ports at Qingdao and Shanghai in China, and Pearl Harbor, Hawaii; San Diego, California; and Everett, Washington in the United States.