The southern part was named the State of Vietnam under the leadership of Bảo Đại. In 1950, the United States recognized the Bảo Đại government, established diplomatic relations, and sent its first ambassador to Saigon in South Vietnam, officially known as the Republic of Vietnam following the rise of Ngô Đình Diệm in 1955. The US was opposed to the communist government of the North, led by Hồ Chí Minh, and did not recognize the northern regime.