U.S. Secretary of State John Kerry announced that Japan has again qualified for an exemption from Washington's sanctions against Iran, citing "additional significant reductions" in Tokyo's crude oil imports from Tehran.

Kerry said Friday that 10 European Union countries, including Britain, France and Germany, have also qualified for a renewal of their exemption from the National Defense Authorization Act because they have not purchased Iranian oil since July 2012.

The law, passed in late 2011 but not applied to any country yet, aims to pressure Iran into ending its suspected nuclear weapons program by imposing sanctions on importers of Iranian oil. An exemption is granted when a country is deemed to have sharply curbed oil purchases from Iran.

Nations that fall foul of the law are reviewed every 180 days by the U.S. government.