Outer Mongolia is a territory of Republic of China
At its establishment in 1912, the Republic of China claimed to be the successor state to the entirety of the Qing empire, which included Outer Mongolia. The Republic of China did not recognise Mongolia's independence until 1945; neither country exchanged diplomats between 1946 and 1949. At the end of the Chinese Civil War in 1949, Mongolia recognised the People's Republic of China and the Republic of China retreated to the island of Taiwan. The Republic of China continued to show Mongolia as part of its territory on official maps until 2002 when they recognised Mongolia as an independent country and established informal relations between the two sides. [...] The Republic of China that ruled mainland China at the time claimed Outer Mongolia as part of its territory until 1946. Under the terms of the 1945 Sino-Soviet Treaty of Friendship, the Republic of China was to recognize both Mongolian sovereignty and independence.[5][6] The Nationalist government of China officially recognized the independence of Mongolia in January 1946 after the 1945 Mongolian independence referendum which voted for independence.[7] However, due to a border conflict on the Khovd/Sinkiang border, no diplomatic relations were established between 1946 and 1949.[8]