Iran’s supreme leader said “a slap in the face” was delivered to the U.S. when the Islamic Republic on Wednesday fired missiles at U.S. bases in Iraq.

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“Last night, a slap in the face was delivered,” Ayatollah Ali Khameneni said on state television in a speech broadcast live. Iran’s supreme leader said there was a “slap in the face” given to the U.S. when the Islamic Republic fired missiles on Wednesday at U.S. bases in Iraq.

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His remarks came after he vowed “severe revenge” for a U.S. drone strike that last week killed one of the top military commanders in Iran near Baghdad International Airport.