Istanbul: Western powers and Iran are meeting again on Saturday to hash out Tehran's promised "new initiatives" on its nuclear activities, albeit with little hope in the West for a breakthrough in the deadlock.

"The Iranian delegation will have new initiatives and we hope that the other party will have a constructive approach," said Iran's top negotiator in nuclear talks on Wednesday, raising hopes that Tehran might have a plan to change dynamics.

What Tehran will bring to the table on Saturday, however, remained unclear after Saeed Jalili's words, but the fact that the talks were starting again after a 15-month break is seen in its own right as a crucial opportunity to lower the tension.

But do not get too many illusions, warns a senior European diplomat, pointing to a lack of "positive signals" from Tehran that compromises will be made to finally lift off Western fears surrounding Iran's nuclear activities.

The so-called P5+1 powers -- permanent UN Security Council members Britain, China, France, Russia and the United States plus Germany -- suspect that Iran's nuclear programme is aimed at concealing its real purpose of producing atomic weapons.

They have imposed increasingly severe economic sanctions on the Islamic republic to pressure it to halt activities, notably uranium enrichment -- moves that instead pushed Iran to accelerate its nuclear pursuit, which it says has no military dimensions.

Angered by the pressure, Tehran announced yesterday that it was halting oil exports to EU nations, a move that was portrayed in Iran as pre-emptive punishment against the West for imposing an oil embargo on the Islamic republic that is to come into full effect on July 1.

Earlier this week, Washington noted that they have no problem with Iran's production of peaceful, civilian nuclear power as long as it can prove that and satisfy the world that it does not intend to make weapons.

"From our perspective, it's relatively straightforward, if in fact their program is purely peaceful, for them to be able to demonstrate it to everybody's satisfaction," State Department Spokesperson Victoria Nuland stated.

For Iran's part, the aim of the talks was that "Iran gain its rights and the P5+1 have its stated concerns alleviated" over Tehran's nuclear programme, according to Iran's foreign minister, Ali Akbar Salehi.

Those rights include access to peaceful nuclear energy for Tehran, which sees uranium enrichment as a "right" that cannot be taken away, and wants to keep its military sites off limits to atomic energy inspections, triggering fears that Iran is indeed trying to produce nuclear warheads.