TEHRAN: Iran's President Hassan Rouhani said Wednesday the leak of an audio recording of his foreign minister sought to sow domestic "discord" during talks aimed at reviving a nuclear deal.

The controversial comments by top diplomat Mohammad Javad Zarif, in which he said the military was too influential in diplomacy, were leaked as Iran and world powers are engaged in talks on reviving a 2015 nuclear accord.

The talks, in Vienna, seek to return the United States to the agreement -- which Washington abandoned under former president Donald Trump -- and persuade Tehran to comply with nuclear obligations it retreated from in retaliation.

"Stealing a document, a tape, it is something that has to be investigated," President Rouhani told a cabinet meeting in televised remarks.

"Why (was it leaked) at this time? In my opinion, this tape ... could have been published a week ago as well."

But "it was published right when the Vienna (talks) were at the height of their success, so that it creates discord inside" Iran, he emphasised.

"We can only lift sanctions through unity".