U.S. Congress on Thursday overwhelmingly passed the Iran sanctions bill, paving way for the Obama administration to take unilateral sanctions on Tehran over its controversial nuclear program.

The bill, which was passed by 408-8 in the House of Representatives and by 99-0 in the Senate, would be send to President Barack Obama to sign into law.

Under the bill, those businesses that help supply Iran with refined petroleum or help develop the country's own refining capacity would be penalized. Also, any financial institutions that do business with the Iranian Islamic Revolutionary Guard Corps or other blacklisted Iranian banks could be denied access to the U.S. financial system.

"We are passing these sanctions because we believe we must stop Iran from developing a nuclear weapon - a weapon that would surely threaten the national security of the United States and of Israel, " said Senate Majority Leader Harry Reid.

The United States, Israel and other Western countries worry that Tehran may obtain the uranium fuel needed for nuclear weapons by the same process to purify uranium. The Iranian government insists its nuclear program is for peaceful purpose.

As part of efforts to compliance with the UN Security Council Resolution 1929, the Obama administration last week extended sanctions on more Iranian individuals and firms due to Tehran's suspected nuclear program.

The additional sanctions target Post Bank of Iran, Islamic Revolutionary Guard Corps entities and individuals, five Islamic Republic of Iran Shipping Lines front companies and so on, according to a statement released by the U.S. Treasury Department.

The resolution, which imposes the fourth round of sanctions on Tehran, prohibits Iran from investing abroad in nuclear and enrichment operations and calls on Iran, once again, to refrain from continuing its uranium-enrichment program.

The resolution prohibits all UN member states from selling to Iran eight categories of heavy weapons, including battle tanks, attack helicopters, and missile systems.