TEHRAN, Iran - The United States strongly warned Iran on Wednesday against closing a vital Persian Gulf waterway that carries one-sixth of the world's oil supply, after Iran threatened to choke off traffic through the Strait of Hormuz if Washington imposes sanctions targeting the country's crude exports.
The increasingly heated exchange raises new tensions in a standoff that has the potential to spark military reprisals and spike oil prices to levels that could batter a fragile global economy.
Iran's navy chief said Wednesday that it would be "very easy" for his country's forces to close the Strait of Hormuz, the passage at the mouth of the Persian Gulf through which about 15 million barrels of oil pass daily. It was the second such warning by Iran in two days, reflecting Tehran's concern that the West is about to impose new sanctions that could hit the country's biggest source of revenue, oil.
"Iran has comprehensive control over the strategic waterway," Adm. Habibollah Sayyari told state-run Press TV, as the country was in the midst of a 10-day military drill near the waterway.
The comments drew a quick U.S. response.
"This is not just an important issue for security and stability in the region, but is an economic lifeline for countries in the gulf . . . ," Pentagon press secretary George Little said.
"Interference with the transit or passage of vessels through the Strait of Hormuz will not be tolerated."
Separately, Lt. Rebecca Rebarich, a Bahrain-based U.S. Navy Fifth Fleet spokeswoman, said the Navy was "always ready to counter malevolent actions to ensure freedom of navigation."
Rebarich declined to say whether the U.S. force had adjusted its presence or readiness in the Persian Gulf in response to Iran's comments, but said the Navy "maintains a robust presence in the region to deter or counter destabilizing activities, while safeguarding the region's vital links to the international community."
Iran's threat to seal off the gulf, surrounded by oil-rich gulf states, reflects its concerns over the prospect that the Obama administration will impose sanctions over its nuclear program that would severely hit its biggest revenue source. Iran is the world's fourth-largest oil producer, pumping about four million barrels a day.
Gulf Arab nations appeared ready to at least ease market tensions. A senior Saudi Arabian oil official said that gulf Arab nations were ready to step in to offset any potential loss of exports from Iran. The official spoke on condition of anonymity because he was not authorized to comment on the issue.
Saudi Arabia, which has been producing about 10 million barrels per day, has an overall production capacity of more than 12 million barrels per day and is widely seen as the only OPEC member with sufficient spare capacity to offset major shortages.
What remains unclear is what routes the gulf nations could take to move the oil to markets if Iran goes through with its threat.
About 15 million barrels per day pass through the Hormuz Strait, according to the U.S. Energy Information Administration.
There are some pipelines that could be tapped, but gulf oil leaders, who met in Cairo on Saturday, declined to say whether they had discussed alternate routes or what they may be.
The Saudi official's comment, however, appeared to allay some concerns. The U.S. benchmark crude futures contract fell $1.98 by the close of trading Wednesday on the New York Mercantile Exchange, but still hovered just below $100 per barrel.