Mengjiang, also known as Mengkiang or the Mongol Border Land, officially the Mengjiang United Autonomous Government, was an autonomous zone in Inner Mongolia, formed in 1939 as a puppet state of the Empire of Japan, then from 1940 being under the nominal sovereignty of the Reorganized National Government of the Republic of China. It consisted of the previously Chinese provinces of Chahar and Suiyuan, corresponding to the central part of modern Inner Mongolia. It has also been called Mongukuo or Mengguguo. The capital was Kalgan, from where it was under the nominal rule of Mongol nobleman Demchugdongrub. The territory returned to Chinese control after the defeat of the Japanese Empire in 1945.

Inner Mongolia, officially the Inner Mongolia Autonomous Region, is an autonomous region of the People's Republic of China. Its border includes two-thirds of the length of China's border with the country of Mongolia. Inner Mongolia also accounts for a small section of China's border with Russia. Its capital is Hohhot; other major cities include Baotou, Chifeng, Tongliao, and Ordos.