U.S. President Barack Obama on Thursday signed the new Iran sanction bill into law which is described by him as "striking at the heart" of Iranian government' s nuclear ability. The bill, signed in the East Room of the White House, imposes tough new sanctions "striking at the heart of Iranian government ability to fund and develop its nuclear program", Obama said in a statement released by the White House. The legislation was approved by U.S. Senate and House in quick succession On June 24. "We are showing the Iranian government that its actions have consequences," Obama said, warning that if Iran persists its current course, "the pressure will continue to mount, and its isolation will continue to deepen." "There should be no doubt -- the United States and the international community are determined to prevent Iran from acquiring nuclear weapons," he said. The new sanctions, described by Obama as the "toughest" ones ever passed by the congress, penalize international firms assisting Iran's energy industry and ban U.S. banks from dealing with foreign banks linked to its Revolutionary Guards or nuclear programs. The measures are seen as aimed at cutting Iran's access to imports of gasoline and isolating it further from the international financial system. Iran, though a major oil producer, heavily relies on imports of refined oil products such as gasoline. In the statement, Obama accused Iran of being the only one signatory to the NPT (Non-Proliferation Treaty) that has been unable to convince the international nuclear watchdog that its nuclear program is for peaceful purposes. "To date, Iran has chosen the path of defiance. That is why we have steadily built a broader and deeper coalition of nations to pressure the Iranian government," he said. On June 9, the UN Security Council adopted a resolution, imposing the fourth round of sanctions on Iran since 2006. On June 16, U.S. Treasury Secretary Timothy Geithner announced that the U.S. government will extend sanctions on more Iranian individuals and entities, including the Post Bank of Iran, Revolutionary Guards commanders, Iranian shipping companies and so on. The new sanctions imposed by U.S. congress and government go far beyond the UN resolution both in scale and scope. However, Obama added in the statement that the door to diplomacy is still open, urging Iran to meet its international obligations. "That is the Iranian government's choice. And it remains our hope that they choose this path, even as we are clear-eyed about the difficult challenges ahead," Obama said.