Iran announced Sunday that it has delivered its first domestically mined raw uranium to a processing facility, claiming it is now self-sufficient over the entire nuclear fuel cycle.

The step displays Iran's determination to master nuclear technology without outside help, including by enriching its own uranium, just a day before world powers meet Iranian officials in Geneva in another attempt to persuade them to freeze that work.

Nuclear chief Ali Akbar Salehi said the uranium ore concentrate, known as yellowcake, was produced at the Gachin uranium mine in southern Iran and delivered to the uranium conversion facility in the central city of Isfahan for reprocessing.

Salehi, head of the Atomic Energy Organization of Iran, said the delivery was evidence that last week's assassination of a top Iranian nuclear scientist and the wounding of another in mysterious bombings will not hamper Iran's nuclear progress.

"Today, we witnessed the shipment of the first domestically produced yellowcake ... from Gachin mine to the Isfahan nuclear facility," said Salehi, whose comments were broadcast live on state television.

Salehi, who is also the country's vice president, said the step meant Iran was now self-sufficient over the entire nuclear fuel cycle _ from extracting uranium ore to enriching it and producing nuclear fuel.

He added that the message to those meeting with Iran in Geneva on Monday and Tuesday was that they cannot stop Iran's nuclear work.

"No matter how much effort they put into their sanctions ... our nuclear activities will proceed and they will witness greater achievements in the future," he said in an interview with state-run Press TV after the announcement.

Salehi said the activity will be carried out under the supervision of the U.N. nuclear watchdog, the International Atomic Energy Agency.

Iran's nuclear chief said a bigger uranium mine at Saghand, in central Iran, will be inaugurated "in the not too distant future."

The Gachin uranium mill near Bandar Abbas processes ore extracted from a nearby mine into yellowcake. The processing is part of the early stages before actual enrichment of uranium.

Yellowcake is then taken to the Isfahan facility to be processed into uranium hexaflouride, which later can be turned into a gas used as feedstock for enriching uranium.

Uranium enriched to low grades is used for fuel in nuclear reactors, but further enrichment makes it suitable for atomic bombs.

The United States and some of its allies accuse Iran of using its civil nuclear program as a cover to develop nuclear weapons. Iran has denied the accusation, saying its nuclear program is geared solely toward generating electricity and producing medical isotope to treat patients.