Tehran, Feb 9 (DPA) Iran Tuesday started the 20 percent uranium enrichment process, the head of the country's Atomic Energy Organisation said.

'The process started in the research hall in the Natanz plant and a cascade of 164 centrifuges have been prepared for the 20 percent enrichment process,' Ali-Akbar Salehi told ISNA, apparently on his way to the Natanz plant.

'This cascade can produce 3 to 5 kilograms of 20 percent uranium per month for the Tehran medical reactor,' he added.

He said the process would be supervised by inspectors of the International Atomic Energy Agency (IAEA), stationed in the capital Tehran.

Foreign Ministry spokesman Ramin Mehmanparast said the new enrichment process had nothing to do with the IAEA-brokered plan to ship low-enriched uranium to Russia and France for processing later into fuel for the Tehran medical reactor.

'The talks on the uranium exchange deal could still be continued but as we have to build new nuclear power plants in the near future for covering our energy and medical needs, we also have to consider the relevant fuel for these plants,' Mehmanparast said.

Salehi claimed on Monday that Iran would build 10 new enrichment plants within the next Persian year which starts on March 21.

'Some plants need uranium with a (enrichment) grade of 3.5 percent and others would need a 20 percent grade, therefore we have to act according to our needs,' Mehmanparast added.

Iran has been sending conflicting signals on its latest enrichment drive. The foreign ministry said that the new enrichment process had nothing to do with the fuel swap, but Salehi claimed the higher-grade enrichment would be stopped as soon as the swap deal was realised and implemented.

Mehmanparast rejected Western charges that Iran's position was just a delaying tactic and termed the charges as 'political games and merely rhetoric'.

'We have clear plans and we have clear nuclear rights and we cannot wait forever for others to make up their minds (whether to cooperate with Iran or not),' he said.

'The issue of the medical Tehran reactor is a humanitarian one as we cannot make sick patients wait for political agreements but should rather seek their cure,' the spokesman added.

Mehmanparast also said that plans by world powers to impose renewed sanctions on Iran would be futile.

'Such moves would be a mistake and just lead into another dead-end,' he said while reiterating that such threats would not make Iran withdraw from its nuclear projects.