Iran has no desire to carry out its threat of closing the Strait of Hormuz to head off fresh Western economic sanctions because doing so would damage the regime's own interests, US-based experts say.

Iran is brandishing the vital shipping route -- a chokepoint for one fifth of the world's traded oil -- as a pawn in the battle being played out against the United States and other leading nations over Tehran's nuclear ambitions.

But the potential effects of taking firm action has left Tehran blowing hot and cold on the issue and could be part of a wider series of threats that Iran is willing to make to defend its ground, according to analysts.

"Iran's perception is that the US and its allies are waging economic warfare on the Islamic Republic and that the regime is at risk -- their ability to export oil has always been a red line for them," said Michael Eisenstadt, a senior fellow at the Washington Institute for Near East Policy.

But "there are all kinds of reasons why Tehran would probably not close the strait as long as they have the ability to export some oil."

"They also import almost all their products through the ... Gulf, so they would really be a self-inflicted wound on them if they were to do this," Eisenstadt said.

"A more likely possibility is that Iran might engage in harassment of US forces, maybe a covert harassment campaign," he told a conference hosted by the Atlantic Council in Washington on Tuesday.

The killing of an Iranian nuclear scientist, which Tehran blamed on the United States and Israel, has added to an already heated diplomatic battle over Tehran's nuclear ambitions -- which it insists are for non-military purposes.

Iran's apparent openness to resuming talks with the United States, Russia, China, France, Britain and Germany, also indicates it does not intend to shut down the strategic trading route, according to Eisenstadt.

The talks last took place in Turkey in January 2011.

But the prospect of new Western sanctions -- the EU could as early as Monday impose new penalties on Iran -- has increasingly seen Tehran use the possible disruption of oil supplies as a bargaining chip.

Mark Gunzinger, senior fellow at the Center for Strategic and Budgetary Assessments, a think-tank focused on US national security, said the situation in the Gulf was a major concern.

"Closing the strait cuts both ways, their economy is very dependent on energy exports as well, as well as imports of refined energy," said Gunzinger.

"I don't personally take what he (Iranian President Mahmoud Ahmadinejad) says seriously, but you do have to take seriously their (nuclear) ambitions.

"The trend line is worrisome. Ten years from now you might not want to put two aircraft-carriers right in the ... Gulf."

The threat is just one tool in Iran's box to deter a US missile strike on its nuclear facilities, according to Bruce Riedel, a former CIA officer.

"The Iranians, I think, very deliberately use the specter of closing the Strait of Hormuz as a codename for something much bigger," said Riedel, a senior fellow at the Saban Center for Middle East Policy at the Brookings Institution.

"They're talking about all the things they could do on the southern littoral of the Gulf, from missile strikes into Abu Dhabi, into refining centers," or supporting terror groups that could hit Thailand, Lebanon or the United States, Riedel said, noting that US efforts in Afghanistan could also suffer.

"They don't have to close the Strait of Hormuz to make sure that the price of gasoline in the US goes through the roof," Riedel said.

"The Iranians are superbly placed to make the war in Afghanistan, which is already difficult, impossible.

"If there is a second country providing sanctuary and safe heaven for the insurgency, the chances of success on the timeline the administration has laid out is virtually nil," Riedel said.

"They can turn out the light literally on half of Afghanistan whenever they want to," he added.