While the United States exports and imports maritime goods from more than 175 countries, the vast majority of the trade is with relatively few countries. In 2007, nearly three-quarters (72 percent) of the container import TEUs were with 10 countries, and over half (55 percent) of the container export TEUs were with 10 countries. The top five overall U.S. containerized cargo trading partners in 2007 were all Asian countries: China (mainland),11 Japan, Hong Kong (China), South Korea, and Taiwan. China (mainland) was the leading containerized merchandise trading partner, accounting for 47 percent of U.S. maritime import TEUs, up from 25 percent in 2000. China accounted for 18 percent of the export TEUs in 2007, down slightly from 2005 (figure 13 and figure 14).
Between 2000 and 2007, while China's share grew of total U.S. container trade, the other top five trading partners saw declines in their total maritime containerized cargo with the United States. Japan is now the second largest trading partner for U.S. oceanborne containerized exports, having been overtaken by China in 2003. In 2007, the U.S. maritime container imports from China alone were larger than those from more than 170 countries combined (i.e., those countries grouped into "other" (figure 13)).
U.S. imports and exports with major trading partners vary by types of goods, and this affects the types of vessels (for example, container, dry bulk, general cargo, or tanker), number of port calls, and the seaports the vessels use. For instance, while most U.S.-Canada maritime trade involves agricultural products, lumber, and petroleum products, most U.S.-Germany maritime trade involves manufactured products such as automobiles and machinery. In addition, U.S. maritime imports from Japan were valued at over $7,000 per ton, but U.S. exports to Japan were valued at $800 per ton, reflecting differences in the types of goods and the growth in high-value containerized imports to U.S. ports. Major U.S. maritime imports from Japan include passenger cars, car parts, and electronic equipment, and major U.S. maritime exports to Japan include agricultural products, industrial machinery, and chemicals.