The International Atomic Energy Agency (IAEA) on Monday called for Iran to sign a framework agreement on steps to remove concerns over controversial aspects of the country's nuclear program.
The IAEA also urged Iran to allow international inspectors to visit a military site where nuclear bomb-relevant research works had allegedly been conducted.
Yukiya Amano, head of the IAEA, told the quarterly board meeting that another round of talks between Iran and the UN nuclear agency, aiming to clarify possible military dimensions to Iran's nuclear program, has been scheduled for June 8 in Vienna.
"I invite Iran to sign and implement the Structured Approach document as soon as possible and to provide early access to the Parchin site, " Amano said in the opening speech of the board meeting.
Recalling his meetings with senior officials in Tehran on May 21, in which Iran and the IAEA decided to agree on such a document, Amano said he was assured that agreement would be expedited and that the remaining differences between Iran and the IAEA would not be an obstacle to reaching agreement.
One priority issue for IAEA in recent talks with Iran is the agency's demand for access to Iran's Parchin military site southeast of Tehran.
Media said the IAEA has received reports that Iran had tested explosives which could be used to set off a nuclear charge.
Iran denied such reports, and insisted access to Parchin would only be granted if Iran and the IAEA agree on certain conditions and steps.
At a press conference after the opening session of the board meeting, Amano said satellite images indicate buildings are being demolished and soil removed at Parchin.
"Our agency has very highly developed instruments that are able to pick up tiny atomic particles. We have seen activity in Parchin recently, and have concerns that these could hinder our inspections," he said.
Meanwhile, Iran's envoy to the IAEA Ali-Asghar Soltanieh said a new chapter has begun in the Iran-IAEA cooperation while warning against technical issues being politicized.
"Third parties should not interfere in the Iran-IAEA technical cooperation to resolve the nuclear issue; this kind of noise and allegations are baseless," the envoy told Iran's official Islamic Republic News Agency (IRNA).
"Certain elements are trying to distort the constructive atmosphere of cooperation between Iran and the agency through political controversy," he said, in a clear reference to Iran's western foes.
The result of the IAEA-Iran talks over technical aspects of nuclear inspections could impact wider political discussions over the future of Iran's nuclear program.
Iran held nuclear talks with the United States, Britain, France, Russia and China plus Germany, known as P5+1, in Baghdad on May 23-24.
The six world powers tabled a package of incentives to Iran in a bid to settle the disputes over its nuclear program, while Iran also announced its readiness for further discussions of the problem of 20-percent enrichment of uranium.
The next round of talks between Iran and the six countries is scheduled to be held in Moscow from June 18-19.