Iran and the United States have had no formal diplomatic relations since 1980. Pakistan serves as Iran's protecting power in the United States, while Switzerland serves as the United States' protecting power in Iran. Contacts are carried out through the Iranian Interests Section of the Pakistani Embassy in Washington, D.C., and the US Interests Section of the Swiss Embassy in Tehran. As of 2018, Supreme Leader of Iran Ali Khamenei banned direct talks with the United States.