The White House on Tuesday renewed its state of emergency with Iran -- declared in 1979 and renewed periodically since then.
"This is a routine renewal of the policy and is not new or connected in any way to the Geneva discussion," an Obama administration official said, referring to the recent nuclear talks between world powers and Iran in Switzerland. "The previous order did not expire — we must renew it to prevent it from expiring."
The United States ended diplomatic ties with Iran on April 7, 1980. This occurred after militants seized control of the U.S. Embassy in Tehran on November 4, 1979 and took dozens of embassy workers hostage.
There have been tensions for years between the United States and Iran over Tehran's nuclear aspirations.
The United States and allies have long believed Iran wants to build nuclear weapons. Iran, however, says it only wants to use nuclear power for peaceful purposes.
Progress toward reaching an agreement over the nuclear program has been made in recent months after the election of President Hassan Rouhani, seen as more moderate and pragmatic than his predecessor.