After the establishment of the People's Republic of China, both countries confirmed their mutual recognition on October 6, 1949. However, the Republic of China used its Security Council veto in 1955, to stop the admission of the Mongolian People's Republic to the United Nations on the grounds it recognized all of Mongolia —including Outer Mongolia— as part of China. This was the only time the Republic of China ever used its veto. Hence, and because of the repeated threats to veto by the ROC, Mongolia did not join the UN until 1961 when the Soviet Union agreed to lift its veto on the admission of Mauritania (and any other newly independent African state), in return for the admission of Mongolia. Faced with pressure from nearly all the other African countries, the ROC relented under protest. Mongolia and Mauritania were both admitted to the UN on 27 October 1961. (see China and the United Nations)