Congress has voted to slap sanctions on Iran's energy, shipping and financial industries.
The House passed the bill 421-6 on Wednesday. A short time later, the Senate approved the bill by voice vote and planned to send it to President Barack Obama for his signature.
The legislation builds on the current penalties directed at financial institutions that do business with Iran's central bank.
Lawmakers argue that increasing the economic pressure on Iran will force it to abandon its suspected nuclear weapons program.