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 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 Northern China. other countries constituting Northeast Asia can be said to be Russian far east, Mongolia, Japan, North Korea and South Korea.
The Economic Research Institute for Northeast Asia defines the region as Russia, Mongolia, Japan, Korea and China.
Northeast Asia is one of the most important economic regions of the world that constituted 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 strong economic growth in the region is expected to double or triple this share.
In biogeography, Northeast Asia generally refers to roughly the area spanning Japan, the Korean Peninsula, Northeast China, and the Russian Far East between Lake Baikal in Central Siberia and the Pacific Ocean.
Northeast Asia is mainly covered by temperate forest, taiga, and the Eurasian steppe. In the region's far North, there is also tundra. There is a vast contrast with temperatures between summer and winter. It is also a mountainous area.