Iran on Tuesday termed a Russian nuclear proposal as not concrete, saying Tehran would not accept it unless it was improved, the official IRNA news agency reported.

"Iran has not received any concrete proposal so far from Russia, " Foreign Ministry spokesman Hamid-Reza Asefi was quoted as saying.

Asefi said Russia's proposal, which was delivered to Iran on Dec. 24, 2005, must be improved before Tehran could accept it.

A Russian delegation will arrive here on Saturday to present formally the proposal, which called on the two countries to establish a joint venture in Russia to enrich uranium for Iran.

"Iran would not accept any proposal that calls only for mere enrichment inside Russia but will consider one that offers a complementary and workable plan," he said.

The Russian proposal was made in a bid to defuse a looming crisis over the Iranian nuclear issue by securing Iran's right to enrich uranium as well as providing what the European Union (EU) and the United States have asked for as objective guarantees that Iran's nuclear research will not be diverted to military usage.

Iran's chief nuclear negotiator Ali Larijani on Sunday termed Russia's proposal as immature, saying it contained "serious problems" and calling on Moscow to further complement and support it.

"Iran's right for having its own nuclear fuel cycle is irrevocable and should be acknowledged. Iran did not want to depend on others," Larijani said.

Meanwhile, Iran's state television reported on Tuesday that Iran said it has informed the International Atomic Energy Agency ( IAEA), the UN nuclear watchdog, of its plan to resume nuclear fuel research in coming days.

Iran's latest move came despite warnings from European officials that any uranium enrichment activities, including fuel research, could endanger the ongoing diplomatic efforts to resolve Tehran's nuclear issue.

The EU, which has been acting as the broker of the Iranian nuclear issue, has voiced readiness to accept the Russian proposal.

Enriched uranium can be used both for generating electricity and for building nuclear weapons.

The United States accuses Iran of developing nuclear weapons secretly, a charge rejected by Tehran as politically motivated.

Source: Xinhua