TEHRAN, Nov 2: Iran on Tuesday vowed never to give up its "right" to enrich uranium but offered hope of progress in critical nuclear talks with European countries which want the Islamic Republic to permanently halt the activity.

Top nuclear negotiator Hossein Mousavian said Iran could agree to maintain a suspension of uranium enrichment for half a year, going some way towards meeting the key demand laid out by Europe's three main states.

His comments came as Iran prepared for a new round of talks in Paris on Friday with the European states which want Tehran to renounce uranium enrichment entirely, in return for an assistance package for its nuclear energy activities.

Iran was prepared to halt uranium enrichment during negotiations with Britain, France and Germany that "could last up to at most six months, not more," Mr Mousavian told AFP.

"Cessation is rejected, indefinite suspension is rejected, suspension shall be a confidence-building measure and a voluntary decision by Iran and in no way a legal obligation, and this has to be clear in our understanding," he added.

Depending on the level of purification, enriched uranium can be used either as fuel for a civilian reactor or as the explosive core of a nuclear bomb. Iran insists it only wants to generate electricity.

Mr Mousavian's comments were echoed by President Mohammad Khatami who said: "Our nation must be given the assurance that it will not be stripped of its right (to enrich uranium)."

But of Friday's new round of talks, Mr Khatami told reporters: "I am optimistic... Both sides are showing flexibility."

"Neither the government nor the nation will allow us to renounce our national right, which is also a matter of national pride. Any suspension that might take place will be voluntary."

Washington charges that Iran is using its nuclear programme as a cover for efforts to develop a nuclear bomb, allegations vehemently denied by Tehran which points out it has the right under the Nuclear Non-Proliferation Treaty (NPT) to enrich uranium for peaceful purposes.

The European Union, represented by Britain, France and Germany, is trying to work out a deal to keep the UN's atomic agency, which meets in Vienna on Nov 25, from deciding to take the dossier to the Security Council.

In return for full suspension of uranium enrichment by Iran, the EU is offering peaceful nuclear technology, including nuclear fuel, as well as trade advantages and support on security issues.

Mr Mousavian said the European trio would have to offer more in the package if Tehran was to agree to a deal. "We have explained to them that the package can not be accepted as it is, it is completely unbalanced," he said.

He predicted that chances of a deal in the talks was "50-50".

The conciliatory comments came after Iranian lawmakers in the conservative-dominated parliament passed a bill on Sunday backing the resumption of uranium enrichment, a key phase in the nuclear fuel cycle.

Mohamed ElBaradei, the head of the UN nuclear watchdog who has set a November 25 deadline for Iran to meet international demands on its nuclear programme, called on Monday for the suspension to remain in place. Meanwhile, European Union foreign ministers gathered on Tuesday in Brussels ahead of an EU leaders' summit this week to tackle aid for Iraq but also Iran's nuclear drive.

German Foreign Minister Joschka Fischer said the international community should accept Iran's "legitimate right to use nuclear power for peaceful purposes according to the international agreements".-AFP