State visit by Ngo Dinh Diem to the United States
Ngô Đình Diệm, the president of South Vietnam, made a state visit to the United States, the main ally of his government, in 1957. Diệm received a glowing welcome and was heaped with praise as a leader of a "free country" in the midst of the Cold War.
Source: Wikipedia — State visit by Ngo Dinh Diem to the United States (CC BY-SA 4.0)