President Barack Obama ordered a freeze on all Iranian government and central bank assets held in the U.S. or any foreign branch of a U.S. entity, the White House announced today. Previously, only assets belonging to sanctioned Iranian entities or individuals were frozen. The order signed by the president yesterday blocks all property and interests in property belonging to the Iranian government, its central bank, and all Iranian financial institutions, even those that havent been specifically designated for sanctions by the U.S. Treasury. Longstanding U.S. regulations already prohibited American citizens or entities from virtually all direct and indirect transactions involving Iran or the government of Iran, aside from those exempted under general licenses for transactions involving food, medicine, remittances and humanitarian relief. The measure was mandated as part of Iran sanctions legislation that was passed by Congress and signed by the president Dec. 31.