TEHRAN - Senior inspectors from the International Atomic Energy Agency (IAEA) will arrive in Iran on Friday to visit nuclear sites, including the Natanz uranium enrichment facility, a senior Iranian official said on Tuesday.
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The visit follows Iran's declaration last week that it had enriched uranium for use in power stations for the first time, stoking Western suspicions of a covert atomic bomb project.

Iran insists it wants nuclear technology for civilian purposes to satisfy its booming demand for electricity.

"We will discuss Iran's enrichment of uranium to 3.5 percent," said the official, who asked not to be named.

IAEA chief Mohamed ElBaradei, who visited Iran last week, said inspectors from the U.N. nuclear watchdog had taken samples and would report back to the IAEA's board on whether the Iranians had indeed achieved 3.5 percent enrichment.

The U.N. Security Council has urged Iran to stop enrichment work and has asked ElBaradei to report on Iranian compliance by April 28. The IAEA director said Iran had told him it would step up efforts to answer questions on its atomic plans.

Iran has repeatedly vowed to pursue its nuclear activities but would cooperate with the IAEA, as a signatory to the nuclear Non-Proliferation Treaty (NPT).

"The deputy head of the IAEA and the inspectors will discuss the remaining issues," the official said, calling the visit a routine part of Iran's commitment to international treaties.

The state IRNA news agency identified the IAEA official as Olli Heinonen, ElBaradei's deputy for safeguards issues. One diplomat said Heinonen's presence suggested Iran was ready to provide some missing information.

The IAEA says it cannot verify Iran's nuclear programme is entirely peaceful despite three years of investigating but it has found no hard proof of efforts to build atomic weapons.

In February, Tehran ended snap inspections of its nuclear facilities after it was referred to the Security Council, which can impose sanctions.

The United States will press other major world powers at a meeting in Berlin of the council's five permanent members and Germany on Tuesday to consider targeted sanctions against Iran.

Russia and China oppose punitive measures against Tehran.

Experts say it would take Iran two decades to produce enough highly enriched uranium for one bomb from its current 164 centrifuges. But Iran says it will to install 3,000 centrifuges, which could make enough material for a warhead in one year.

Iranian officials say the Natanz enrichment plant has a capacity for 54,000 centrifuges.