Commercial relations between Iran and the United States are restricted by American sanctions and consist mainly of Iranian purchases of food, spare parts, and medical products as well as American purchases of carpets and food. Sanctions originally imposed in 1995 by President Bill Clinton were renewed by President Bush, who cited the "unusual and extraordinary threat" to American national security posed by Iran. The 1995 executive orders prohibit American companies and their foreign subsidiaries from conducting business with Iran, while banning any "contract for the financing of the development of petroleum resources located in Iran". In addition, the Iran and Libya Sanctions Act of 1996 (ILSA) imposed mandatory and discretionary sanctions on non-American companies investing more than $20 million annually in the Iranian oil and natural gas sectors.