Solana in Tehran (Reuters)

Tehran, June 6 (Reuters): Proposals by six world powers today to end a dispute over Iran’s nuclear fuel enrichment had positive points but also some “ambiguities” that must be removed, Tehran’s chief negotiator said.

The proposals, which have not been made public but include incentives and penalties, seek to persuade Iran to give up enriching uranium, which the West fears will be used to build atomic bombs. Tehran says its nuclear aims are purely civilian.

European Union foreign policy chief Javier Solana presented Iran’s chief negotiator Ali Larijani with the package, agreed by the US, Russia, China, Britain, France and Germany.

“The proposals had some positive steps in them and some ambiguities which should be removed,” Larijani said. He did not elaborate on the “ambiguities”.

“We hope, after we study the proposal in detail, we will have another round of talks and negotiations to achieve a balanced and logical conclusion,” he said.

The US, Iran’s arch foe which has been at the forefront of efforts to pressure the Islamic republic to give up enrichment, said it was heartening Iran was taking the incentives package seriously.

But Washington reiterated the Iranian government needed to suspend nuclear enrichment activities before any direct talks. Progress will depend on overcoming deep mutual mistrust.

Iran covered up sensitive nuclear fuel research and development work from the United Nations for almost 20 years until an Iranian exile group blew the whistle.

Tehran has impeded probes by the UN atomic energy agency since which have pointed to military links with nuclear work and possible secret activity, although no hard evidence of diversions into bombmaking has been found.

For its part, Washington, which broke ties with Tehran in 1980, says it wants a diplomatic solution but refuses to rule out military action.

“If the Iranians agree to suspend enrichment-related and reprocessing activities, then we’ll be able to discuss more openly what the incentives are and we certainly hope that that’s the case,” White House spokesman Tony Snow told reporters travelling with President George W. Bush.

So far, Iran has refused to give up uranium enrichment that can be used to make fuel for nuclear power stations or, if enriched to a sufficiently high level, material for bombs. Iran says it is a national right.