By Hashem Kalantari and Fredrik Dahl
The statement by commander-in-chief Mohammad Ali Jafari was likely to fuel tension over Tehran's disputed atomic ambitions, coming shortly after Iran again said it would press on with nuclear work the West suspects is aimed at making bombs.
Military analysts say the United States could unleash vastly superior firepower against Iran, but say the Islamic Republic could hit back against Washington's forces in Iraq and by disrupting oil supplies vital to the world economy.
Iran's armed forces have "the possibility of closing the Strait of Hormuz, easily and on an unlimited basis," state radio quoted Jafari as telling a news conference.
As well as threatening to shut the Strait of Hormuz, Jafari said the elite Guards force had tested a naval weapon that could destroy any vessel in a range of 300 km (190 miles), media said. Iran's recent missile tests rattled oil markets.
About 40 percent of world oil exports passes through the Strait of Hormuz, a choke point at the southern end of the Gulf, flanked by the coastlines of Iran and Oman. Much of it goes to Asia, the United States and western Europe.
The United States and Israel have not ruled out military action if Iran continues to enrich uranium, which can have both military and civilian uses, in defiance of repeated demands by the United Nations Security Council.
Iran, the world's fourth-largest oil producer, says its aims are peaceful and has warned it would retaliate if attacked. It ignored an informal August 2 deadline to reply to an offer proposed by six world powers aimed at defusing the row.
'SEVERE DISRUPTION'
"In view of the proximity of the Strait of Hormuz … to our shores, this distance is within the range of an assortment of weapons and its closure for us is very feasible and we face no limitations from the point of view of time," Jafari said.
The U.S. military has pledged to keep the Strait open.
Andrew Brookes of the International Institute for Strategic Studies, a think-tank in London, doubted Iran would want to close a shipping lane through which it exported its own oil.
"I think it has the ability to cause severe disruption in the Gulf," Brookes said.
"But the West led by the U.S. would respond so forcefully that Iran would find that its ports and ships were hit in such a fashion that the disruption would not continue," he said.
Energy consultant Mehdi Varzi said he did not believe Iran could keep the Strait closed but a conflict would hurt supplies.
It would immediately impact prices by sending insurance rates for oil tankers "through the roof" and reducing shipments.
U.S. forces are stationed in several countries around the Gulf, including Bahrain where the U.S. Navy Fifth Fleet is based. Iran says U.S. forces are in range of its weapons.
Some military analysts say the easiest way Iran could strike back would be by targeting U.S. forces in Iraq using proxies and allies, even though they said a stable neighbor was in Iran's long-term interest.
Jafari said the naval weapon the Guards had tested was Iranian built but did not give details, saying "no vessel would be safe and would be sent to the depths."
(Reporting by Hashem Kalantari and Fredrik Dahl; Writing by Fredrik Dahl; Editing by Sami Aboudi)
