The US lower house of congress has approved legislation to levy sanctions on foreign companies that help supply fuel to Iran, as part of efforts to punish Tehran over its nuclear program.
The bill, approved in the House of Representatives by a 412-12 vote on Tuesday, permits Barack Obama, the US president, to impose sanctions on firms that directly provide Iran with fuel.
The move expands a US law that aims to punish foreign companies that invest more than $20m a year in Iran's energy sector.
Iran has some of the world's biggest oil reserves but a lack of refining capacity means that it has to import 40 per cent of its fuel to meet domestic demand.
The bill also authorizes Obama to use sanctions against companies that provide insurance and tankers for shipments.
Targeted sanctions
"This bill has one overriding goal: to prevent Iran from achieving a nuclear weapons capability," Howard Berman, a Democrat who sponsored the legislation, said.
The US senate is expected to pass a similar bill, but it is not clear when the vote will go ahead.
Nancy Pelosi, the house speaker, said the US should "use all the tools at our disposal, from diplomacy to sanctions, to stop Iran's march toward nuclear capability".
"By targeting Iran's ongoing dependence from largely imported refined petroleum we reduce the chance that Iran will acquire the capacity to produce nuclear weapons," she said.
There have been concerns that the bill could upset US trading partners and allies and damage efforts towards a multilateral stand against Iran's nuclear program.
Berman said after the vote that he was open to creating exceptions for companies from countries that have their own stringent sanctions on the Iran.
Exceptions considered
Supporters of the bill said that many Iranians who are upset the country's disputed presidential election in June would likely turn their anger toward the Iranian government if further fuel sanctions were imposed.
The US, the European Union, Russia and China have all expressed concerns over Tehran’s nuclear weapons program.
Tehran says its nuclear program is only for peaceful purposes and has rejected an offer to have most of its low-enriched uranium sent abroad by the end of the year for further enrichment.
In recent years, companies such as British Petroleum (BP) and Reliance, an Indian firm, have backed away from supplying Iran, but other firms have filled the gap in imports.
Trafigura and Vitol, both European companies; International Petroleum Group, based in Kuwait; and Malaysia's Petronas are among those that are currently supplying Iran.
PHOTO CAPTION
File photo of the Bushehr nuclear power plant in Iran.
Al-Jazeera