Iran and the United Nations nuclear watchdog will have further talks over Tehran's disputed nuclear programme on 21 May in Vienna, Iranian media said on Monday.
There was no immediate confirmation from the International Atomic Energy Agency (IAEA), leaving unclear whether a firm date for the next meeting had already been agreed.
The IAEA-Iran talks are separate from, but have a bearing on, diplomatic negotiations between Tehran and six world powers aimed at a broad settlement to the decade-old dispute to head off the risk of a new Middle East war.
Western powers suspect Iran is trying to develop the capability to produce nuclear weapons under the guise of a declared civilian atomic energy programme. Iran denies this, saying it seeks only electricity from uranium enrichment.
But its refusal to curb sensitive nuclear activity with both civilian and military applications and its lack of openness with IAEA inspectors have drawn U.N. and Western sanctions.
Last week, a diplomatic source told Reuters that a meeting between the Vienna-based IAEA and Iran in May was a possibility, but that no date had yet been fixed.
If it were to take place, it would be the 10th round of negotiations between the two sides since early 2012, so far without a deal that would enable the U.N. watchdog to resume its long-stalled investigation into Iran's nuclear facilities.
Iran's Mehr and ISNA news agencies gave no further details in their reports on Monday.
A Western diplomat in Vienna held out little hope the next round of talks would be more successful than previous rounds.
If confirmed, it would take place shortly before the IAEA is expected to issue its next quarterly report on Iran's nuclear programme and ahead of a June 3-7 meeting of the IAEA's 35-nation, policymaking Board of Governors, when the Iranian nuclear dispute will once again be on the agenda.
"We have seen this game before," said the diplomat, from a Western country critical of the Islamic Republic.
"Iran seems to have no intention of engaging in real dialogue...(It) just maintains the illusion of movement in order to deflect tough responses from the international community."
Officials at Iran's IAEA legation were not immediately available for comment. The last round of IAEA-Iran negotiations, in February, yielded no breakthrough.
Speaking in Geneva on Monday, European Union nuclear non-proliferation official Jacek Bylica said the EU was "deeply concerned" about Iran's nuclear programme.
"Our objective remains to reach a comprehensive long-term settlement, which would restore international confidence in the exclusively peaceful nature of Iran's nuclear programme," Bylica said, according to a prepared statement.
Some analysts say the Islamic Republic's leadership may be unwilling or unable to make important decisions in nuclear negotiations before its presidential election in June.