The UN atomic agency said Monday that it was discussing with Iran possible dates for what would be the 10th round of talks since late 2011 on Tehran's suspected nuclear bomb-making efforts.

"I can confirm we are discussing possible dates of a meeting with Iran," International Atomic Energy Agency spokeswoman Gill Tudor said.

She declined to comment however on Iranian media reports suggesting that the two sides would meet on May 21 in Vienna, where the agency has its headquarters.

Iran has consistently rejected as unfounded what the IAEA calls "overall, credible" evidence that until 2003 and possibly since, it conducted nuclear weapons research.

The IAEA closely monitors Iran's declared nuclear facilities but wants Iran also to grant access to sites, scientists and documents involved in these alleged military activities.

Iran denies wanting or ever having sought the bomb, and accuses the IAEA of basing its conclusions on faulty intelligence from foreign spy agencies -- intelligence it complains it has not been allowed to see.

Nine rounds of talks, the latest in February, since the publication of a major IAEA report in November 2011 on these alleged activities, have produced no breakthrough.

Parallel diplomatic efforts between Iran and six major powers -- the US, China, Russia, Britain, France and Germany -- are focused more on Iran's current activities.

The latest round in Kazakhstan in early April ended without result, with chief negotiator and EU foreign policy head Catherine Ashton saying the two sides remained "far apart".

A possible meeting between Iran and the IAEA comes ahead of the release in late May of the agency's latest quarterly report, which is expected to show that Tehran has continued to expand its nuclear programme.