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 programme.
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 expand 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 authorises Obama to use sanctions against companies that provide insurance and tankers for shipments.
"This bill has one overriding goal: to prevent Iran from achieving a nuclear weapons capability," Howard Berman, a Democrat who sponsored the legislation, said.
"If these sanctions are implemented it will help the most hardline elements in Iran"
Afshin Rattansi, journalist
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 programme.
Berman said after the vote that he was open to creating exceptions for companies from countries that have their own stringent sanctions on the Islamic Republic.
Afshin Rattansi, a journalist based in Iran, told Al Jazeera: "I think what is happening in the House of Representatives demonstrates yet again a complete lack of comprehension of what is happening in the Middle East.
"Gordon Brown was at the climate summit in Copenhagen talking about more sanctions, if these sanctions are implemented it will help the most hardline elements in Iran.
"President [Mahmoud] Ahmadinejad is, some say, threatening to bring in an end to the subsidy or at least decrease the subsidy in Iran for gasoline for the people. He has been trying to do that, but there has been lots of opposition to that. Well, he's now going to be able to blame the Obama administration for having to do that."
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.
|Iran has been accused by the US and others of seeking to build a nuclear weapon [EPA]
"Before the regime's brutal effort to crush protests following the June 12 Iranian election, an Iranian cab driver who couldn't buy gasoline would probably curse the Americans," Mark Dubowitz, who heads the Foundation for Defence of Democracies, said.
"After witnessing the brutal crackdown and his fellow citizens dying in the streets, he now might very well blame the regime."
The US, the European Union, Russia and China have all expressed concerns over Tehran’s nuclear weapons programme, which they fear could lead to the production of an atomic weapon.
Tehran says its nuclear programme 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.