TOKYO, Oct. 22 (Kyodo) - Japan's trade surplus with the United States in September fell for the first time in two months in the wake of the Sept. 11 terrorist attacks on the U.S., according to a preliminary report released Monday by the Finance Ministry. The surplus with the U.S. decreased 9.6% from a year earlier to 682.9 billion yen, the report says. "Various factors influence trade, so I cannot say for sure" that the Sept. 11 attacks affected trade activities, a ministry official said. Both exports and imports, however, showed double-digit falls. Exports fell 11.9% to 1,214.4 billion yen, the largest drop since October 1999's 12.5% decline, while imports dropped 14.6% to 531.5 billion yen, the largest fall since February 2000's 21.1% drop. The official said the ministry will closely monitor developments, such as impacts of the Sept. 11 attacks and slowing global demand for information technology-related products.