Tehran: Iran's Parliament will begin debating a draft bill requiring the government to immediately halt oil exports to Europe, a prominent lawmaker said on Thursday, as Tehran weighs its options following the European Union's decision to stop importing oil from the country.

The EU embargo, announced on Monday, was the latest attempt to try to pressure Iran over a nuclear programme the United States and its allies argue is aimed at developing nuclear weapons but which Iran says is for purely peaceful purposes. It came just weeks after the US approved, but has yet to enact, new sanctions targeting Iran's Central Bank and, by extension, its ability to sell its oil.

Many Iranian lawmakers and officials have called for an immediate ban on oil exports to the European bloc before its ban fully goes into effect in July, arguing that the 27 EU nations account for only about 18 percent of Iran's overall oil sales and would be hurt more by the decision than Iran.

China, a key buyer of Iranian crude, has blasted the embargo.

"The bill requires the government to stop selling oil to Europe before the start of European Union oil embargo against Iran," lawmaker Hasan Ghafourifard told the Parliament's website, icana.ir. Debate on the bill is to begin on Sunday, he said.

The US sanctions had outraged Iranian officials, prompting repeated threats from various officials that the country could shutter the vital Strait of Hormuz if measures are enacted that affect its oil exports. Roughly a fifth of the world oil passes through the narrow waterway, and the US and others have warned Iran they will not allow it to impede the free flow of traffic in the area.

Iran is OPEC's fourth largest producer and most of its crude goes to Europe and Asia.

Iranian officials have said the sanctions will have no effect on the economy and they will find other willing buyers.

Analysts and diplomats also have played down the likelihood that Iran will actually move to close the strait, a step that could bring it into direct conflict with US and other Western naval and ground forces stationed in and around the Persian Gulf.

"The door to dialogue remains open for Iran," German Foreign Minister Guido Westerwelle said in Berlin on Thursday. "But it also is clear that we in the world cannot accept Iran's government reaching for nuclear weapons. So the sanctions are necessary."

"If they are applied comprehensively and supported by as many as possible in the world, that makes the probability of success all the greater," Westerwelle said after meeting his Australian counterpart, Kevin Rudd.