The Embassy of the United States in Phnom Penh is the sole diplomatic mission of the United States to Cambodia. It is located in the capital Phnom Penh. The United States has had a physical diplomatic presence in Cambodia ever since relations were initiated in 1950, which was promoted to an embassy in 1952. A history of strained and suspended relations throughout the Cold War led to the embassy being forced to close at various times, including permanently between 1965 and 1969 and again between 1975 and 1991. Before the latter closure, embassy staff were evacuated in an operation similar to the more famous US evacuation of Saigon. As US-Cambodia relations improved and security threats increased through the 2000s, a new purpose-built complex was constructed. It was opened in 2006, being one of the first American diplomatic missions constructed around the post-9/11 "Standard Embassy Design" model.