Clinton says Japan, E.U. working to comply with Iran sanctions WASHINGTON (Reuters) - U.S. Secretary of State Hillary Clinton on Tuesday pledged to aggressively implement new U.S. sanctions on Iran but noted that some allies such as Japan face "unique situations" as they seek to reduce Iranian oil imports. President Barack Obama on December 31 signed into law the harshest in a series of U.S. sanctions on Tehran over its nuclear program, targeting foreign financial institutions that do business with Iran's central bank or other blacklisted Iranian financial entities. The new U.S. sanctions have set off a scramble among countries with significant Iranian oil imports to voluntarily reduce such purchases so they would be exempted from the penalties. For non-petroleum transactions, from February 29 the law requires the president to punish private banks that "knowingly conducted or facilitated any significant financial transaction with the Central Bank of Iran" or other blacklisted entities. For oil-related transactions, from June 28 the law allows the president to punish foreign banks that carry out financial transactions "for the purchase of petroleum or petroleum products from Iran" provided several conditions are met. Obama has until March 30 to decide whether the price and supply levels of non-Iranian oil and fuels such as gasoline, diesel and jet fuel in global markets are sufficient for countries to "significantly" reduce their Iranian purchases. "We are implementing the new Iran sanctions aggressively," Clinton told a Senate panel, outlining steps aimed at hobbling Iran's ability to make an atomic bomb by squeezing revenues from its oil exports. Iran says its nuclear program is geared purely to develop power stations and for medical purposes. Clinton repeated that U.S. intelligence assessments held that Iran had not yet decided to pursue a nuclear weapon. But she said it was important to work with other countries to keep up the pressure. "I think that there's a very clear-eyed view of Iran and Iranian objectives and that's why the president's policy is so clear and adamant that the United States intends to prevent Iran from obtaining a nuclear weapon," she said. Japan, the world's third-biggest oil importer, last year bought almost 9 percent of its crude from Iran and its dependence on fuel imports has increased because almost all its power-generating nuclear reactors have been shut after the Fukushima nuclear disaster a year ago. Japan's Nikkei business daily reported last week that Japan could cut its Iranian oil imports by a more-than-expected 20 percent in its drive to win a U.S. exemption. Clinton said U.S. teams had held "very frank" discussions with their counterparts in a number of capitals on the need to slash Iranian imports and cut dealings with Iran's central bank. "We've seen a lot of action, a broad range of countries are making decisions to reduce their dependence on Iranian crude, unwind their dealings with the Central Bank of Iran," she said. The EU member states - some of those countries were dependent up to 30-35 percent on Iranian crude - and Japan have been among the most visible. They've been taking extraordinary steps to try to comply with our sanctions and deny revenue to Iran. Clinton said the United States understood that some countries could not stop Iranian oil imports "cold turkey" and it was working hard to help them line up alternate supplies. We have some unique situations. Look at Japan," she said, noting the impact of the earthquake and ensuing nuclear crisis. "They have been reducing their imports from Iran in the range of 15-20 percent since last year because we have been working with them and talking to them," Clinton said. Indeed, Japanese data showed Iran crude imports fell in January by 22.5 percent compared with a year earlier to about 339,000 barrels per day. Clinton said challenges remained on lining up alternative oil suppliers, citing the slow resumption of Libyan oil production and new sanctions on Syria, but overall the U.S. sanctions effort appeared to be working. "European and Asian companies are actually moving more quickly in reducing their imports and their purchases than we thought they'd be able to," Clinton said. We're just relentlessly pressing them ... we're going to do the very best we can to help them. Additional reporting by Susan Cornwell; Editing by Mohammad Zargham and Neil Fullick