DUBAI, United Arab Emirates — A spokeswoman for the U.S. Navy's 5th Fleet is warning Iran that any disruption of traffic flowing though the Strait of Hormuz, a vital oil route, "will not be tolerated."
Iran's navy chief warned earlier Wednesday that the Islamic Republic is ready and willing to close the strategic waterway if the West imposes new sanctions targeting Tehran's oil exports over the country's suspect nuclear program. He insisted that it would be easy to cut off the passageway for one-sixth of the world's oil flow.
"Anyone who threatens to disrupt freedom of navigation in an international strait is clearly outside the community of nations; any disruption will not be tolerated," said fleet spokeswoman Lt. Rebecca Rebarich.
She said the U.S. Navy is "always ready to counter malevolent actions to ensure freedom of navigation."
Vice President Mohamed Reza Rahimi, Iran's navy chief, issued his country's first threat to close the strait on Tuesday.
With concern growing over a possible drop in Iranian oil supplies, a senior Saudi oil official said Gulf Arab nations are ready to offset any loss of Iranian crude.
World oil prices were mixed Wednesday. In New York, benchmark crude rose 6 cents to $101.40 a barrel. Brent crude fell 12 cents to $109.15 a barrel in London.
"Closing the Strait of Hormuz is very easy for Iranian naval forces," Adm. Habibollah Sayyari told state-run Press TV. "Iran has comprehensive control over the strategic waterway," the navy chief said.
The threats underline Iranian concern that the West is about to impose new sanctions that could target Tehran's vital oil industry and exports.
Western nations are growing increasingly impatient with Iran over its nuclear program. The United States and its allies have accused Iran of using its civilian nuclear program as a cover to develop nuclear weapons. Iran has denied the charges, saying its program is geared toward generating electricity and producing medical radioisotopes to treat cancer patients.
The U.S. Congress has passed a bill banning dealings with the Iran Central Bank, and President Barack Obama has said he will sign it, despite his misgivings. Critics warn it could impose hardships on U.S. allies and drive up oil prices.
The bill could impose penalties on foreign firms that do business with Iran's central bank. European and Asian nations import Iranian oil and use its central bank for the transactions.
Iran is the world's fourth-largest oil producer, with an output of about 4 million barrels a day. It relies on oil exports for about 80 percent of its public revenue.
Iran has adopted an aggressive military posture in recent months in response to increasing threats from the United States and Israel that they may take military action to stop Iran's nuclear program.
Iran's navy is in the midst of a 10-day drill in international waters near the strategic oil route. The exercises began Saturday and involve submarines, missile drills, torpedoes and drones. The war games cover a 1,250-mile (2,000-kilometer) stretch of sea off the Strait of Hormuz, northern parts of the Indian Ocean and into the Gulf of Aden near the entrance to the Red Sea as a show of strength and could bring Iranian ships near U.S. Navy vessels in the area.
Iranian media are describing how Iran could move to close the strait, saying the country would use a combination of warships, submarines, speed boats, anti-ship cruise missiles, torpedoes, surface-to-sea missiles and drones to stop ships from sailing through the narrow waterway.
Iran's navy claims it has sonar-evading submarines designed for shallow waters of the Persian Gulf, enabling it to hit passing enemy vessels.
A closure of the strait could temporarily cut off some oil supplies and force shippers to take longer, more expensive routes that would drive oil prices higher. It also potentially opens the door for a military confrontation that would further rattle global oil markets.
Iran claimed a victory this month when it captured an American surveillance drone almost intact. It went public with its possession of the RQ-170 Sentinel to trumpet the downing as a feat of Iran's military in a complicated technological and intelligence battle with the U.S.
American officials have said that U.S. intelligence assessments indicate the drone malfunctioned.
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