 After the Iranian Revolution in 1979, the United States ended its economic and diplomatic ties with Iran, banned Iranian oil imports and froze approximately $ 11 billion of its assets. In 1996, the U.S. Government passed the Iran and Libya Sanctions Act (ILSA) which prohibits U.S. (and non-U.S.) companies from investing and trading with Iran in amounts of more than $ 20 million annually. Since 2000 exceptions to this restriction have been made for items including pharmaceuticals and medical equipment.
