Iran will block the strategic Strait of Hormuz at the mouth of the Gulf, the passageway through which a fifth of the world's oil flows, if its interests are seriously threatened, a senior Iranian military commander said.
"We do have a plan to close the Strait of Hormuz," state media quoted General Hasan Firouzabadi as saying on Saturday.
"But Iran, acting rationally, will not close the corridor through which 40 per cent of the world's energy passes, unless its interests are in serious trouble," he said, referring to the country's crucial crude revenues.
The comments by Firouzabadi, the chairman of Iran's Joint Chiefs of Staff, come days after the European Union enforced a total oil embargo against Iran for its refusal to halt its uranium enrichment program.
The comments also come after the US moved new forces into the Gulf to support anti-mine operations in the Gulf to keep the strategic waterway open, the US Navy said Friday.
A fleet spokesman in Manama said the USS Ponce, described as a "afloat forward staging base", had arrived on Thursday after undergoing refitting for its new mission.
"Ponce's primary mission is to support mine countermeasures operations and other missions, such as the ability to provide repair service to other deployed units," the spokesman said in a statement.
"Additionally, Ponce also has the capability to embark and launch small riverine craft."
Vice Admiral John Miller, commander of regional navy forces, said the Ponce boasted "enhanced capability to conduct maritime security operations, and gives us greater flexibility to support a wide range of contingencies with our regional partners".
A halt in crude oil imports from Iran is intended to increase pressure on the Islamic Republic to stop enriching uranium to the 20 per cent level, an issue at the center of an international dispute.
Western powers fear material produced at that level, well above the 3.5 per cent enrichment needed for energy-producing reactors, can be turned into weapons-grade material in a matter of months. Iran insists its reactors are only for energy and research.
Iranian lawmakers have prepared a bill that would order the country's military to stop tankers headed to countries that have joined the oil ban.
But Iran's parliament speaker, Ali Larijani, was quoted by Iranian media on Saturday as saying that the proposed bill has not yet been studied by parliament.
Iran's powerful Revolutionary Guard has warned in the past that Tehran would order the closure of the Strait of Hormuz if the country's oil exports are blocked.`