|Al Jazeera's Alan Fisher reports on the rising tensions between the US and Iran in the Gulf over sanctions
The US has strongly warned Iran against closing a vital Gulf waterway, after Iran threatened to choke off traffic through the Strait of Hormuz if the US imposes sanctions targeting the country's crude exports.
The increasingly heated exchange raises new tensions in a standoff that has the potential to prompt military reprisals and push up oil prices to levels harmful to an already fragile global economy.
The Strait of Hormuz is a 6.4km wide channel between Iran and Oman at the mouth of the Gulf through which more than one-third of the world's tanker-borne oil, or about 15 million barrels of oil, pass daily.
"This is not just an important issue for security and stability in the region, but is an economic lifeline for countries in the Gulf, to include Iran,'' George Little, Pentagon press secretary, said on Wednesday.
"Interference with the transit or passage of vessels through the Strait of Hormuz will not be tolerated,"
Earlier, Mohammad Reza Rahimi, Iran's vice-president, was quoted as saying: "If sanctions are adopted against Iranian oil, not a drop of oil will pass through the Strait of Hormuz."
Iran's navy chief said on Wednesday that it would be 'very easy' for his country's forces to close the strategic Strait of Hormuz, "Iran has comprehensive control over the strategic waterway," Admiral Habibollah Sayyari told state-run Press TV, as the country was in the midst of a 10-day military drill near the strategic waterway.
'No desire for violence'
It was the second such warning by Iran in two days, reflecting Iran's concern that the West is about to impose new sanctions that could hit the country's biggest source of revenue, oil.
"We have no desire for hostilities or violence ... but the West doesn't want to go back on its plan to impose sanctions," Sayyari said.
"The enemies will only drop their plots when we put them back in their place."
"We have no desire for hostilities or violence ... but the West doesn't want to go back on its plan to impose sanctions"
- Admiral Habibollah Sayyari
The threat underlined Iran's readiness to target the narrow stretch of water along its Gulf coast if it is attacked or economically strangled by Western sanctions.
A spokesperson for the US Navy's Fifth Fleet responded to the threat by warning Iran that any disruption of traffic flowing though the Strait of Hormuz "will not be tolerated".
"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,'' Rebecca Rebarich said.
She said the US navy is "always ready to counter malevolent actions to ensure freedom of navigation."
The US maintains a navy presence in the Gulf in large part to ensure that passage remains free.
Iran rejected in September US calls for a military hotline between the capitals to defuse any "miscalculations" that could occur between their military forces in the Gulf.
Iranian ships and aircraft dropped mines in the sea on Tuesday as part of the drill, according to a navy spokesman.
Although Iranian war games occur periodically, the timing of these is seen as a show of strength as the US and Europe prepare to impose further sanctions on Iran's oil and financial sectors.
The last round of sanctions, announced in November, triggered a pro-government protest in front of the British embassy in Tehran during which Basij militia members overran the mission and ransacked it.
Britain closed the embassy as a result and ordered Iran's mission in Britain shut as well.
An Iranian legislator's comments last week that the navy exercises would block the Strait of Hormuz briefly sent oil prices soaring before that was denied by the government.
While the foreign ministry said such drastic action was "not on the agenda", it reiterated Iran's threat of "reactions" if the current tensions with the West spilled over into open confrontation.
EU ministers said on December 1 that a decision on further sanctions would be taken no later than their January meeting but left open the idea of an embargo on Iranian oil.
Countries in the 27-member EU receive 450,000 barrels per day of Iranian oil, about 18 per cent of the country's exports, much of which go to China and India.
China, the biggest buyer of Iranian crude, has said against "emotionally charged actions" that might aggravate tension in the nuclear standoff with Iran.
Russia, for its part, has cautioned against "cranking up a spiral of tension", saying this would undermine the chances of Iran co-operating with efforts to ensure it does not build atom bombs.
Most of the crude exported from Saudi Arabia, Iran, the United Arab Emirates, Kuwait and Iraq - together with nearly all the liquefied natural gas from lead exporter Qatar - must pass through the Strait of Hormuz.