UN nuclear chief says Iran visit could produce 'important agreements'

UN nuclear watchdog chief Rafael Grossi said on Saturday he had "constructive" talks with Iranian officials in Tehran after the discovery of uranium particles enriched to near weapons-grade level.

The two-day visit by the head of the International Atomic Energy Agency (IAEA) chief director general comes as the Vienna-based organisation seeks greater cooperation with Iran over its nuclear activities.

"By having a constructive discussion... and having good agreements, like I am sure we are going to have, we are going to be paving the way for important agreements," Grossi told a news conference alongside Iran's top nuclear official Mohammad Eslami.

In his series of meetings with Iranian officials, Grossi met President Ebrahim Raisi.

Raisi acknowledged that "cooperation is a two-way street... (and) can continue based on maintaining the agency's independence and the rights of the Iranian nation," the political deputy of Iran's presidency, Mohammad Jamshidi tweeted.

A diplomatic source earlier told AFP that the meeting with Raisi was aimed to "relaunch the dialogue" on Iran's atomic work and to "reset the relationship at the highest level".

Grossi arrived in Iran on Friday amid deadlock in negotiations on reviving a landmark 2015 accord on Iran's nuclear activity, known formally as the Joint Comprehensive Plan of Action, or JCPOA.

Uranium particles enriched up to 83.7 per cent — just under the 90 per cent needed to produce an atomic bomb — had been detected at Iran's underground Fordo plant about 100 kilometres south of Tehran, according to a confidential IAEA report seen by AFP this week.

Iran denies wanting to acquire atomic weapons, and says it had made no attempt to enrich uranium beyond 60-per cent purity.

Iran's government has said, however, that "unintended fluctuations... may have occurred" during the enrichment process.

The discovery came after Iran had substantially modified an interconnection between two centrifuge clusters enriching uranium, without declaring it to the IAEA.

And during his visit he aimed to secure "more access to the (Fordo) site, more inspections," the diplomatic source said.