"Uranium enrichment is not necessarily for weapons purposes," Mohammad Eslami said on Wednesday in an interview with AFP on the sidelines of the International Atomic Energy Agency's (IAEA) general conference in Vienna.

"We are doing it for research and the production of various isotopes for nuclear industry applications," he said.

Tensions between Iran and the IAEA have repeatedly flared since a 2015 deal curbing Tehran's nuclear programme in exchange for sanction relief fell apart.

In recent years, Tehran has decreased its cooperation with the IAEA, while significantly ramping up its nuclear programme, including amassing large stockpiles of uranium enriched to 60 percent, which is close to the 90 percent needed to develop an atomic bomb.

The rapid expansion of Iran's nuclear programme has no "credible civilian justification", according to the UN nuclear watchdog.

Amid the impasse, the IAEA's board of governors in June adopted a resolution critical of Iran.

Despite the restrictions on inspections since 2021 and the barring of UN inspectors, the IAEA continues to "daily monitor" Iran's nuclear programme, at a level that exists "nowhere else in the world," Eslami stressed.

- Iran deal 'not dead' -

"Our work is completely transparent. It is not as if we were producing a material with covert objectives," Eslami told AFP.

He said Iran was in discussions with IAEA chief Rafael Grossi to organise his visit to the country in the near future, where he is expected to meet President Masoud Pezeshkian.

Since Pezeshkian's election in July, Iran has said it was willing to relaunch talks to revive the Iran nuclear deal it reached with world powers in 2015.

The landmark deal -- also known under the acronym JCPOA -- started to unravel in 2018 when then US president Donald Trump unilaterally withdrew from it and reimposed sanctions, and Iran retaliated by stepping up its nuclear activities.

Efforts to revive the deal -- bringing the United States back on board and Iran back into compliance -- have so far been fruitless.

Eslami, however, told AFP that "the JCPOA is not dead".

"As soon as the others resume their obligations, we will act accordingly", he said, stressing that "it is not possible for them to expect us to keep our commitments" when they themselves have reinstated sanctions.

But Western powers have deplored the "absence" of positive concrete signs from Tehran.

"Patience has its limits, and we will not stand by while Iran continues to obfuscate," the United States, Britain, France and Germany warned in a joint statement last week.

Experts say a resumption of talks seems unlikely before the US presidential elections, amid a sharp deterioration in Iran's relations with Europe and the US.