Iran sent conflicting signals in a dispute with the West over its nuclear ambitions, vowing to stop oil exports soon to 'some' countries but postponing a parliamentary debate on a proposed halt to crude sales to the European Union.

The Islamic Republic declared itself optimistic about a visit by U.N. nuclear experts that began Sunday but also warned the inspectors to be 'professional' or see Tehran reducing cooperation with the world body on atomic matters.

Lawmakers have raised the possibility of turning the tables on the EU which will implement its own embargo on Iranian oil by July as it tightens sanctions on Tehran over the nuclear program.

But India, the world's fourth-largest oil consumer, said it would not take steps to cut petroleum imports from Iran despite U.S. and European sanctions against Tehran.

The International Atomic Energy Agency (IAEA) inspection delegation will try to advance efforts to resolve a row about the nuclear work which Iran says is purely civilian but the West suspects is aimed at seeking a nuclear weapon.

Tension with the West rose this month when Washington and the EU imposed the toughest sanctions yet in a drive to force Tehran to provide more information on its nuclear program.

The measures take direct aim at the ability of OPEC's second biggest Oil exporter to sell its crude.

In a remark suggesting Iran would fight sanctions with sanctions, Iran's oil minister said the Islamic state would soon stop exporting crude to 'some' countries.

Rostam Qasemi did not identify the countries but was speaking less than a week after the EU's 27 member states agreed to stop importing crude from Iran from July 1.

"Soon we will cut exporting oil to some countries," the state news agency IRNA quoted Qasemi as saying.

India, a major customer for Iranian crude, made clear it would not join the wider international efforts to put pressure on Tehran by cutting oil purchases.

"It is not possible for India to take any decision to reduce the imports from Iran drastically, because among the countries which can provide the requirement of the emerging economies, Iran is an important country amongst them," Finance Minister Pranab Mukherjee told reporters on a visit to the Unites States.

The United States wants buyers in Asia, Iran's biggest oil market, to cut imports to put further pressure on Tehran.

DISCUSSION POSTPONED
Iranian lawmakers had been due to debate a bill Sunday that could have cut off oil supplies to the EU in days, in a move calculated to hit ailing European economies before the EU-wide ban on took effect.

But Iranian MPs postponed discussing the measure.

"No such draft bill has yet been drawn up and nothing has been submitted to the parliament. What exists is a notion by the deputies which is being seriously pursued to bring it to a conclusive end," Emad Hosseini, spokesman for parliament's Energy Committee, told Mehr news agency.

Iranian officials say sanctions have had no impact on the country. "Iranian oil has its own market, even if we cut our exports to Europe," Oil Minister Qasemi said.

Another lawmaker said the bill would oblige the government to cut Iran's oil supplies to the EU for five to 15 years, the semi-official Fars news agency reported.

By turning the sanctions back on the EU, lawmakers hope to deny the bloc a six-month window it had planned to give those of its members most dependent on Iranian oil - including some of the most economically fragile in southern Europe - to adapt.

NUCLEAR WATCHDOG
Before departing from Vienna, IAEA Deputy Director General Herman Nackaerts said he hoped Iran would tackle the watchdog's concerns "regarding the possible military dimensions of Iran's nuclear program."

Mehr quoted Foreign Minister Ali Akbar Salehi as saying during a trip to Ethiopia: "We are very optimistic about the outcome of the IAEA delegation's visit to Iran ... Their questions will be answered during this visit."

"We have nothing to hide and Iran has no clandestine (nuclear) activities." Striking a sterner tone, Iran's parliament speaker, Ali Larijani, warned the IAEA team to carry out a 'logical, professional and technical' job or suffer the consequences.

"This visit is a test for the IAEA. The route for further cooperation will be open if the team carries out its duties professionally," said Larijani, state media reported.

"Otherwise, if the IAEA turns into a tool (for major powers to pressure Iran), then Iran will have no choice but to consider a new framework in its ties with the agency."

Iran's parliament has approved bills in the past to oblige the government to review its level of cooperation with the IAEA. However, Iran's top officials have always underlined the importance of preserving ties with the watchdog body.

The head of the state-run National Iranian Oil Company (NIOC) said late Saturday that the export embargo would hit European refiners, such as Italy's Eni, that are owed oil from Iran as part of long-standing buy-back contracts under which they take payment for past oilfield projects in crude.

The EU accounted for 25 per cent of Iranian crude oil sales in the third quarter of 2011. However, analysts say the global oil market will not be overly disrupted if parliament votes for the bill that would turn off the oil tap for Europe.

Potentially more disruptive to the world oil market and global security is the risk of Iran's standoff with the West escalating into military conflict.

Iran has repeatedly said it could close the vital Strait of Hormuz shipping lane if sanctions succeed in preventing it from exporting crude, a move Washington said it would not tolerate.