Two top US senators have offered a bill to impose sweeping new penalties on Iran and thwart its alleged nuclear ambitions.
Senate Banking Committee chairman Tim Johnson, a Democrat, and Alabama senator Richard Shelby, the panel's top Republican, said they had agreed on the measure that would target Iran's Revolutionary Guard Corps, require companies that trade on the US stock exchange to disclose any Iran-related business to the Securities and Exchange Commission, and expand penalties for energy and uranium mining joint ventures with Tehran.
The bill also would deny visas and freeze assets on individuals and companies that supply Iran with technology that could be used to crack down on its citizens, such as tear gas, rubber bullets and surveillance equipment.
Mr Johnson and Mr Shelby said their committee would consider the legislation on Thursday.
"A nuclear-armed Iran would represent a grave threat to regional peace and international security," Mr Johnson said in a joint statement with Mr Shelby. "Iran's continuing defiance of its international legal obligations and refusal to come clean on its nuclear programme underscore the need to further isolate Iran and its leaders."
Mr Shelby said the bill "sends a clear signal through strong measures that Iran must abandon its nuclear weapons programme and its designs for the spread of international terror".
Iran says its nuclear development programme is to produce uranium for non-military uses, not bombs.
A report in November suggested that some of the Islamic republic's alleged experiments could have no other purpose than developing nuclear weapons. Iran contends that its programme is designed to generate electricity. A United Nations inspection team is currently in the country.
Both the Obama administration and the international community have imposed tough sanctions on Iran, but Mr Johnson and Mr Shelby said those penalties had been insufficient to deter Tehran from pursuing a nuclear weapon.
Among the provisions of the legislation is an expansion of US sanctions to include companies involved in joint energy ventures anywhere in the world in which Tehran is a significant partner or investor. The penalties also would apply if Iran were to receive energy technology or information that was not available to the government previously.