London ( CNN ) -- Britain cut all financial ties Monday with Iran over concerns about Iran 's nuclear program , the first time it has ever cut an entire country 's banking sector off from British finance , the British Treasury announced . The move comes days after an International Atomic Energy Agency report highlighted new concerns about `` the possible military dimensions of Iran 's nuclear program , '' the Treasury statement said Monday . The IAEA 's governors approved a resolution last week expressing `` deep and increasing concern about the unresolved issues regarding the Iranian nuclear program . Iran insists its nuclear program is peaceful and has called the U.N. watchdog 's report `` unbalanced '' and `` politically motivated . '' `` The IAEA 's report last week provided further credible and detailed evidence about the possible military dimensions of the Iranian nuclear program , '' British Foreign Secretary William Hague said in a statement . `` Today we have responded resolutely by introducing a set of new sanctions that prohibit all business with Iranian banks . '' U.S. Secretary of State Hillary Clinton and Treasury Secretary Tim Geithner will `` outline new steps the United States is taking to increase pressure on Iran '' on Monday afternoon in Washington , the State Department said . The United States will name Iran , as well as its central bank , as a `` primary money-laundering concern '' but will not place sanctions directly on the central bank , a senior Treasury Department official told CNN . The Obama administration plans to impose fresh sanctions against Iran 's petrochemical industry , diplomatic sources familiar with the plans said Friday . U.S. sanctions already prohibit American companies from doing business with Iran . The British sanctions underline `` the severity of the government 's concerns about Iran 's activities , '' the statement issued by Britain 's chancellor of the exchequer said . All British credit and financial institutions must end their business relationships and transactions with all Iranian banks , their branches and subsidiaries by Monday afternoon , it said . `` Iran 's activities that facilitate the development or production of a nuclear weapon pose a significant risk to the national interests of the UK and countries across the region , '' it said . `` Iranian banks play a crucial role in providing financial services to individuals and entities within Iran 's nuclear and ballistic missile programs , as companies carrying out proliferation activities require banking services . '' The chancellor 's statement said other `` partner countries '' will make similar announcements about banking sanctions against Iran . `` We believe that the Iranian regime 's actions pose a significant threat to the UK 's national security and the international community , '' Chancellor George Osborne said . `` Today 's announcement is a further step to preventing the Iranian regime from acquiring nuclear weapons . '' CNN 's Alex Felton , Jill Dougherty and Elise Labott contributed to this report .
British government to end all banking ties to Iran by Monday morning . Secretary of State Hillary Clinton to outline new steps U.S. is taking to help Iran . The IAEA raises ` ` deep and increasing concern '' over the Iran 's nuclear program . Iran calls U.N. watchdog 's report ` ` unbalanced '' and ` ` politically motivated ''