Iran will send the delegation "in the coming days in order to begin talks and strengthen cooperation with the International Atomic Energy Agency (IAEA)", Amir-Abdollahian told reporters in Tehran.

He did not provide details on the delegation's composition or the precise date of the discussions.

The UN watchdog has been pressing Iran to give answers on the presence of nuclear material at three undeclared sites, a key sticking point that led to a resolution criticising Iran being passed at a June meeting of the IAEA's board of governors.

Amir-Abdollahian expressed hope that the IAEA would be able to resolve "accusations" brought against Iran, and that "we will be able to pass through this stage through technical cooperation".

Iran has repeatedly said it wants the IAEA to drop its interest in the three sites -- a position that the nuclear watchdog says lacks credibility.

After months of friction the two sides met face-to-face in Vienna in September.

"Dialogue has restarted with Iran on clarification of outstanding safeguards issues," IAEA Director General Rafael Grossi tweeted at the time, adding that he had met with the head of Iran's nuclear organisation, Mohammed Eslami.

On-off talks between Tehran and world powers have been underway since April last year to revive the 2015 nuclear deal, which gave Iran much-needed sanctions relief in return for curbs on its atomic programme.

The landmark Vienna accord has been in tatters since then US president Donald Trump withdrew from it in 2018, and Iran later began backing away from its own commitments.

An "exchange of messages" via European Union foreign policy chief Josep Borrell was ongoing "concerning the establishment of a new schedule of Vienna talks", Amir-Abdollahian said.

Borrell has been coordinating efforts to try to revive the deal. Amir-Abdollahian added he was due to speak with Borrell later Wednesday.

The EU in August submitted a final draft of a modified nuclear text for the agreement, but key issues remain between Tehran and Washington, as well as the UN nuclear watchdog.