TEHRAN: Tehran Tuesday accused the United States of abducting an Iranian nuclear scientist who went missing in Saudi Arabia during a minor Muslim pilgrimage, and said Riyadh must also be held accountable.

Shahram Amiri reportedly disappeared from the holy city of Medina early June, just three days after landing in Saudi Arabia.

Foreign Minister Manouchehr Mottaki accused Washington of kidnapping Amiri.

"Based on existing pieces of evidence that we have at our disposal, the Americans had a role in Mr. Amiri's abduction," Mottaki said at a press conference in Farsi which was translated into English by Press TV channel.

"The Americans did abduct him. Therefore we expect the American government to return him."

Mottaki said Amiri had travelled to Saudi Arabia to perform the minor Muslim pilgrimage when he disappeared.

"He disappeared in Saudi Arabia and naturally we ask the Saudi government to look into the case.... Saudi Arabia must be held accountable in this regard... and Iran reserves rights to legally pursue such cases."

Earlier Tuesday, foreign ministry spokesman Ramin Mehmanparast told Mehr news agency that "Riyadh handed over Amiri to Washington" and that he is now one of 11 Iranians sitting in US jails.

Mehmanparast also acknowledged for the first time that Amiri is a nuclear scientist, something which Iranian officials have previously declined to confirm.

Iranian media have previously reported that America's Central Intelligence Agency was involved in the scientist's disappearance.

Amiri left for Saudi Arabia on May 31 and on his arrival was "questioned by Saudi agents at the airport for a longer time than other pilgrims," Iran's hardline Javan newspaper said in October.

"Three days later when he left his hotel in Medina, he never returned," the report said, adding that Amiri was a researcher at Tehran's Malek-Ashtar University of Technology.

The newspaper quoted his wife as saying he was "only a researcher and did not hold any government post."

Several regional Arabic newspapers had speculated that Amiri was a nuclear scientist and he was involved in building Iran's second uranium enrichment plant near the Shiite holy city of Qom which has outraged world powers.

EU foreign ministers meeting in Brussels, meanwhile, agreed on Tuesday that Iran's stance on its nuclear programme requires a clear response, including new "appropriate measures."

"Iran's persistent failure to meet its international obligations and Iran's apparent lack of interest in pursuing negotiations require a clear response, including through appropriate measures," the ministers agreed in a text which will now go forward to a full EU summit on Thursday and Friday.

Mehmanparast had told a separate media conference earlier Tuesday that Iran has no faith in world powers when it comes to resolving the dispute over a proposed nuclear fuel deal.

"We never said we will not do this (nuclear fuel deal)," Mehmanparast said when asked if Iran was still weighing up whether to subscribe to the deal brokered by the International Atomic Energy Agency (IAEA).

World powers had backed the IAEA proposal under which Iran would send most of its low-enriched uranium (LEU) to Russia and France for conversion into nuclear fuel for a research reactor in Tehran.

But Iran rejected the proposal last month, insisting it wanted to hand over its LEU at the same time it receives the 20 percent enriched uranium, and that the handover must take place simultaneously inside Iran.

"The question is the attitude of some Western countries in the past. They have lost trust and have never kept their promises," Mehmanparast said.

"We can't listen to them easily. If they can provide conditions that can gain our trust, we are ready to exchange the fuel."

Western powers suspect Tehran is pursuing nuclear technology to make atomic weapons. Iran denies the charge, saying its ambitions are to gain peaceful nuclear power.

Mehmanparast also dismissed Western threats to impose a fourth set of UN sanctions on Tehran if it does not come clean on its nuclear programme.

"Sanctions are nothing new for Iran," he said.

"If there is another round of sanctions we will be more serious" in pursuing nuclear technology.