The U.S. Senate Thursday unanimously approved tougher economic sanctions on Iran, vowing to penalize foreign financial institutions that do business with Iran's central bank.

In a bid to cut off the bank from the global financial system, the Senate voted 100-0 for an amendment sponsored by Democratic Senator Robert Menendez and Republican Senator Mark Kirk that would allow U.S. President Barack Obama to sanction foreign financial institutions found to have conducted a "significant financial transaction with the Central Bank of Iran."

The sanctions were approved as an amendment to a huge defense bill that passed the Senate on the same day.

The U.S. already bars its own banks from doing business with the Iranian central bank, so the new sanctions would be aimed at discouraging other foreign banks from doing so.

"The Obama administration strongly supports increasing the pressure on Iran, and that includes properly designed and targeted sanctions against the central bank of Iran, appropriately timed as part of a carefully phased and sustainable policy toward bringing about Iranian compliance with its obligations," Undersecretary of State Wendy Sherman told the Senate Foreign Relations Committee in a hearing before the vote.

VietNamNet/Xinhuanet