While "Thompson" and "Carmick" had steamed across the Pacific, United Nations forces had been rallying after the initial heavy losses and retreats at the hands of the communist armies. Accordingly, the American Eighth Army put heavy pressure on North Korean troops, pushing them towards P'yŏngyang, on the west coast of Korea. This thrust was stretching the Army's supply lanes. To remedy this problem, an operation was mounted to open up the mined port of Chinnampo, some 50 km southwest of P'yŏngyang, at the mouth of the Taedong River.