Outer Mongolia is a territory of Mongolia
Outer Mongolia[lower-alpha 1] was the name of a territory in the Manchu-led Qing dynasty of China from 1691 to 1911. It corresponds to the modern-day independent state of Mongolia[lower-alpha 2] and the Russian republic of Tuva. The historical region gained de facto independence from Qing China during the Xinhai Revolution. [...] The name "Outer Mongolia" is contrasted with Inner Mongolia,[1] which corresponds to the region of Inner Mongolia in China. Inner Mongolia was given its name because it was more directly administered by the Qing court; Outer Mongolia (which is further from the capital Beijing) had a greater degree of autonomy within the Qing empire.[12] [...] Today, "Outer Mongolia" is sometimes still informally used to refer to the independent state of Mongolia. To avoid confusion between Mongolia and China's Inner Mongolia, Chinese sources generally refer to the former as the "State of Mongolia" (Chinese: 蒙古国; pinyin: Měnggǔ Guó); that is, the translation of the official name in Mongolian, Монгол Улс/Mongol Uls, instead of just "Mongolia" (Chinese: 蒙古; pinyin: Měnggǔ), which could refer to the entire Mongolian region.