The UN Security Council first joined the US in freezing assets in December 2006 with a freeze on assets belonging to Iranian individuals and companies linked to the country’s nuclear program. It expanded the freeze to 28 more people, companies, and groups in March 2007, including the state run bank, Bank Sepah, as well as firms controlled by the Iranian Revolutionary Guards. The scope was expanded again in March 2008 to another 13 people and 12 companies.