US lawmakers take next step on new Iran sanctions.

Reuters - Lawmakers on the U.S. Senate Banking Committee plan to vote on a new round of sanctions targeting Iran's energy sector, aimed at choking funds they suspect Tehran uses to develop nuclear weapons.

The committee released details of its 61-page bipartisan bill late on Monday, and lawmakers will consider the measures and vote on them at a hearing on Thursday.

"Iran's continuing defiance of its international legal obligations and refusal to come clean on its nuclear program underscore the need to further isolate Iran and its leaders," said Tim Johnson, the Democratic chairman of the committee.

The package comes on the heels of new banking sanctions that the Obama administration is only beginning to implement - a package signed into law on Dec. 31 - as well as tough new embargos by European nations.

But Johnson and Richard Shelby, the top Republican on the committee, said existing sanctions and embargoes have not done enough to force Iran to stop its work on building a nuclear bomb. Iran says its nuclear program is for civilian use only.

The proposed new legislation would require the administration to identify officials, affiliates and agents of Iran's Revolutionary Guard Corps within 90 days, and designate them for sanctions.

The proposed bill would target companies that do business with the IRGC, penalize U.S. companies whose foreign subsidiaries do business with Iran, and sanction energy and uranium mining joint ventures done with Tehran in other parts of the world.

Companies traded on U.S. stock exchanges would have to disclose any activity in Iran to the U.S. Securities and Exchange Commission, which could prompt further sanctions action.

The bill also would sanction companies that supply Iran with equipment - including telecommunications equipment - used to commit human rights abuses.