Inspectors from the UN nuclear watchdog will make a return visit to Tehran to discuss intelligence alleging Iran pursued nuclear weapons studies, diplomats in Vienna confirmed on Friday, dpa reported.
An International Atomic Energy Agency (IAEA) delegation, headed by chief inspector Olli Heinonen, will depart for Iran on Sunday, a diplomat close to the IAEA said.
"They will travel to Iran on Sunday for talks as agreed with Iranian officials," the Vienna-based diplomat said, adding that the topic of discussion would be the alleged weaponization studies.
In a sign of movement on the controversial issue on Tehran's part, Iran and the IAEA are expected to continue talks held earlier this week.
The visit was within the agreement reached with Iran earlier this week, diplomats said.
The two sides held intensive two-day talks over allegations that Iran was pursuing secret nuclear weapons studies.
The IAEA inspectors want answers from Tehran regarding intelligence received from Western member states on alleged studies on uranium conversion, high explosives testing and work on a missile re-entry vehicle, which all have potential nuclear weapons applications.
Iranian Foreign Minister Manouchehr Mottaki, however, termed the visit by Heinonen to Tehran just a routine act and rejected Western press reports that the talks were solely focused on the new allegations.
Mottaki maintained that Iran had already answered all outstanding questions and rejected the "baseless allegations" of a clandestine weapons programme.
However, he did not clarify whether Iran would eventually reply to the allegations by May or not but just said that Tehran would continue cooperation with the IAEA "as a normal member" and within the framework of the Nuclear Non-Proliferation Treaty.
Last week, IAEA General Secretary Mohammed ElBaradei said in Berlin that Iran was making only slow progress in enriching uranium for use in nuclear applications.
ElBaradei repeated his call for Tehran to sign the additional protocol to the Nuclear Non-Proliferation Treaty (NPT) that provides for snap IAEA inspections.
Tehran's enrichment programme was based on the first-generation centrifuges of the P1 type. Iran had increased the number of its centrifuges from 3,000 to 3,300 or 3,400, ElBaradei said.
The five permanent members of the UN Security Council - the United States, Russia, China, Britain and France - along with Germany have been seeking to pressure Tehran to comply with its commitments as a signatory to the NPT.
Iran signed the additional protocol to the NPT in December 2003, but withdrew its support in September 2005, although it remains a signatory to the main NPT.
The Security Council has also passed three rounds of limited sanctions against Iran to increase pressure to come clean about its programme.