Northeast Asia or Northeastern Asia is a geographical subregion of Asia; its northeastern landmass and islands are bounded by the Pacific Ocean.
The term Northeast Asia was popularized during the 1930s by American historian and political scientist Robert Kerner. Under Kerner's definition, "Northeast Asia" included the Mongolian Plateau, the Northeast China Plain, the Korean Peninsula, the Japanese archipelago, and the mountainous regions of the Russian Far East, stretching from the Lena River in the west to the Pacific Ocean in the east.
The definition of Northeast Asia is not static but often changes according to the context in which it is discussed.
In common usage, the term Northeast Asia typically refers to a region which includes Northeast China (Inner Mongolia and Manchuria). Other countries and territories which make up Northeast Asia are the Russian Far East including the Sea of Okhotsk, Mongolia, Japan, North Korea, and South Korea. Parts or the whole of Northern China are also frequently included in sources. The Economic Research Institute for Northeast Asia defines the region as Russia, Mongolia, Japan, Korea, and China.
Prominent cities in this area include Seoul, Pusan, Incheon, Pyongyang, Tokyo, Osaka, Kobe, Kyoto, Yokohama, Hiroshima, Nagasaki, Shenyang, Harbin, Vladivostok, and Ulaanbaatar.
Northeast Asia is one of the most important economic regions of the world, accounting for 25.3% of the world's nominal GDP in 2019, which is slightly larger than the United States. It is also one of the major political centers and has significant influence on international affairs. By the end of the 1990s, Northeast Asia had a share of 12% of the global energy consumption, with a strong increasing trend. By 2030, the major economic growth in the region is expected to double or triple this share.
In biogeography, Northeast Asia generally refers roughly to the area spanning Japan, the Korean Peninsula, Northeast China, and the Russian Far East between Lake Baikal in Southern Siberia and the Pacific Ocean.
Northeast Asia is mainly covered by temperate forest, taiga, and the Eurasian Steppe, while tundra is found in the region's far north. Summer and winter temperatures are highly contrasted. It is also a mountainous area.