( CNN ) -- South Korea on Wednesday announced sanctions against Iran -- including government scrutiny of most financial transactions involving the country -- as part of global efforts to quash Tehran 's suspected nuclear program . A key Iranian bank also will face `` a heavy penalty , '' said South Korean Foreign Ministry spokesman Kim Young-sun , according to state media . The Seoul branch of Iran 's Bank Mellat has allegedly facilitated hundreds of millions of dollars in transactions for Iranian nuclear , missile and defense agencies , the Yonhap news agency said . Korea also will expand a sanctions blacklist to limit the foreign-exchange transactions of more than 100 people and Iranian entities ; step up inspections of suspicious cargo to and from Iran ; put those blacklisted on a travel ban ; and limit investments in Iran 's gas and oil refinery industries . The blacklisted entities include Bank Mellat , the Islamic Revolutionary Guard Corps and the Islamic Republic of Iran Shipping Lines , according to Yonhap . The United States , a key South Korean ally , has lobbied other nations to step up sanctions against Iran . The European Union , Canada and Japan are among those that have done so . Iran is continuing its uranium enrichment activities in defiance of U.N. Security Council resolutions , according to a report released Monday by the International Atomic Energy Agency . Iran has rebuffed international demands to halt its uranium enrichment program , saying it wants the nuclear fuel for peaceful uses . The IAEA is not convinced . In low concentrations , enriched uranium can be used to fuel civilian power plants , but in extremely high concentrations , it can be used to produce a nuclear bomb . `` Based on an overall analysis undertaken by the agency of all the information available to it , the agency remains concerned about the possible existence in Iran of past or current undisclosed nuclear-related activities involving military-related organizations , including activities related to the development of a nuclear payload for a missile , '' the IAEA report said . Last month , the United States extended sanctions against Iran , saying it was targeting a number of Iranian businesses and groups accused of helping organizations such as Hezbollah , Hamas and the Taliban . In June , the United Nations imposed some of its toughest sanctions yet of Iran . The new sanctions include cargo inspections , new controls on Iranian banks , restrictions on the Islamic Revolutionary Guard Corps , a new U.N. panel of experts to help monitor and enforce sanctions , and asset freezes on 40 entities and individuals . Also in June , the U.S. Treasury Department announced sanctions targeting the country 's nuclear and missile programs , identifying more than 20 companies and several individuals allegedly involved with those programs .
Measures include scrutiny of financial transactions and cargo inspections . The United States has been a major exporter of arms to Saudi Arabia since the 1970s. Iran has dismissed suspicions that it is enriching uranium to build a nuclear bomb . The country has defied U.N. Security Council resolutions , the IAEA says .