An Iranian official announced Saturday the talks in Vienna will not resume before a new government takes office in August, following presidential elections last month won by ultra-conservative Ebrahim Raisi.

"We still have a number of questions, issues that we are trying to clarify with Iran, and we will have to wait and start anew with the new team when they are in office," IAEA director general Rafael Grossi told AFP in an interview in Rio de Janeiro during an official visit to Brazil.

The announcement that the process would be resumed only after Raisi takes over "leaves us in a rather uncomfortable situation," he added.

"I'm talking about the agency, I don't know about the others, but I suppose they would rather be negotiating than waiting."

The Islamic republic has been engaged in negotiations since April in Vienna with major powers on reviving its troubled 2015 nuclear agreement.

The 2015 accord offered Tehran international sanctions relief in exchange for limiting its nuclear program, but was torpedoed in 2018 when former US president Donald Trump withdrew from it and reimposed sanctions.

Trump's successor Joe Biden has signaled his readiness to return to the deal and has engaged in indirect negotiations with Iran as the accord's other remaining state parties -- Britain, China, France, Germany and Russia -- hold talks in Vienna.

A sixth round of talks concluded on June 20.

Incumbent President Hassan Rouhani had repeatedly promised he would get the United States to lift sanctions before the end of his term, but last week indicated this would no longer be possible and negotiations would not be complete before he leaves office.

Raisi will take over from Rouhani on August 5.

Ultimate political power in Iran rests with the supreme leader, Ayatollah Ali Khamenei, who gave the green light for both the original nuclear agreement and the efforts to revive it.