The EU is imposing an immediate ban on imports of oil from Iran as a way to pressure the government to halt its nuclear activities. ITV's Ali Smith reports.
Updated at 12:30 p.m. ET: Hours after the European Union imposes an oil embargo and sanctions on Iran's central bank, France, Britain and Germany say they are willing to negotiate with Iran if it is ready to talk seriously about its nuclear program.
"We call on Iran's leadership immediately to suspend its sensitive nuclear activities and abide fully by its international obligations," the European countries say in a joint statement. "Until Iran comes to the table, we will be united behind strong measures to undermine the regime's ability to fund its nuclear program."
In response, the offices of Treasury secretary Timothy Geithner and Secretary of State Hillary Clinton issues the following statement, according to NBC News:
"We welcome today's decision by the European Union to ban imports of Iranian crude oil and petroleum products, freeze the assets of the Iranian central bank, and take additional action against Iran's energy, financial, and transport sectors."
Updated at 12 p.m. ET: Iran says a European Union decision Monday to impose new sanctions over its nuclear program is "psychological warfare," Reuters reports.
"... Imposing economic sanctions is illogical and unfair but will not stop our nation from obtaining its rights," Foreign Ministry spokesman Ramin Mehmanparast is quoted as saying by state television, referring to Iran's nuclear energy ambitions.
Updated at 11 a.m. ET: Russia's Foreign Ministry says the European Union was wrong to impose an oil embargo on Iran over its controversial nuclear program, The Associated Press reports.
"It's apparent that in this case there is open pressure and diktat, aimed at 'punishing' Iran for uncooperative behavior. This is a deeply mistaken policy, as we have told our European partners more than once. Under pressure of this sort, Iran will not make any concessions or any corrections to its policies," the ministry says.
Updated at 9:45 a.m. ET: Israeli Prime Minister Benjamin Netanyahu praised a European Union decision to place sanctions on Iranian oil exports, Reuters reports. "I think this is a step in the right direction," Netanyahu said at a meeting of his Likud faction in parliament. "For now, it is impossible to know what the result of these sanctions will be. Heavy and swift pressure is needed on Iran and the sanctions must be evaluated according to their results."
Netanyahu also said that despite world pressure so far "Iran is continuing undeterred to develop nuclear weapons," Reuters adds.
Updated at 8:30 a.m. ET: A member of Iran's influential Assembly of Experts, former intelligence minister Ali Fallahian, says Tehran should respond to an EU decision to impose sanctions on Iran -- some of which come into force in July -- by stopping oil sales to the bloc immediately. This would deny the Europeans time to arrange alternative supplies and damaging their economies with higher oil prices.
"The best way is to stop exporting oil ourselves before the end of this six months and before the implementation of the plan," the semi-official Fars news agency quoted him as saying, Reuters reports. He also reiterated that Iran could close the Strait of Hormuz, through which a third of all oil tanker traffic passes to importers around the world.
Published at 7:45 a.m. ET: The European Union on Monday adopted an oil embargo against Iran over its nuclear program, a day after U.S., British and French warships sailed into the Persian Gulf.
British Foreign Secretary William Hague on Monday called the measure part of "an unprecedented set of sanctions."
"I think this shows the resolve of the European Union on this issue," he said.
Diplomats say the measures, adopted by the EU's 27 foreign ministers, include an immediate embargo on new contracts for crude oil and petroleum products while existing ones are allowed to run until July.
Tehran denies claims that its nuclear program is aimed at developing weapons, saying it is for peaceful purposes.
In a report that examined how Iran might respond to an EU oil embargo, Professor Paul Stevens, a visiting professor at University College London (Australia) and research fellow at U.K. think tank Chatham House, said it was "extremely unlikely" that Iran would not retaliate.
'Lockerbie-type response' feared
Stevens said that if Iran seriously threatened the transit of oil tankers through the Strait of Hormuz, a vital route for world supplies, this would "rapidly degenerate into a shooting war" between Iran and the U.S., supported by its allies.
He expressed doubts Iran would try to do this, saying it was a "very powerful card that Iran is unlikely to play early in the game."
However, Stevens said Iran had other retaliation options, warning that there "could even be a Lockerbie-type response prompted by elements from within Iran," referring to the bombing ofPan Am flight 103 over Lockerbie, Scotland, which led to 270 deaths. That attack was blamed on Moammar Gadhafi's Libyan regime.
He also said Iran could try to push oil prices upward by creating further instability in Iraq, hitting that country's oil exports; make "serious trouble" for NATO in Afghanistan; and also put "huge pressure" on other Gulf oil exporters and "at worst" threaten oil facilities."
Stevens said the Abqaiq processing facility in Saudi Arabia was "well within Iranian missile range."
On Sunday, the aircraft carrier USS Abraham Lincoln and its battle group sailed through the Strait of Hormuz, despite previous threats from Iran to attack the aircraft carrier Stennis if it returned to the Gulf.
Fmr. National Security Adviser to President Carter, Dr. Zbigniew Brzezinski, and the Washington Post's David Ignatius join Morning Joe to discuss Iran. What will tough sanctions from the West on Iran mean? Is Iran sending the world signals they are willing to negotiate when it comes to nuclear proliferation? The Washington Post's Bob Woodward also joins the conversation.
U.S. military officials said the Lincoln saw no sign of Iranian speed boats that sometimes harass U.S. warships.
The U.K.'s Telegraph newspaper reported that the nuclear-powered Lincoln was accompanied by a British navy ship and a French warship.
A U.K. defense ministry spokesman told the paper that HMS Argyll had joined the U.S. carrier group "to underline the unwavering international commitment to maintaining rights of passage (to the Strait of Hormuz) under international law."
The Associated Press, Reuters and msnbc.com staff contributed to this report.