Chongjin or Chungjin (both: chŭngˈjĕnˈ) [key], Jap. Seishin, city (1993 pop. 582,480), NE North Korea, an ice-free port on the Sea of Japan (or East Sea). It was developed in the 1930s by the Japanese as an iron and steel center. The city has metallurgical plants, chemical factories, and fish canneries, and also produces ships, machinery, and textiles.