Atomic Energy Organization of Iran director Mohammad Eslami said the enrichment levels were related to the needs of the country, in remarks published by the Russian news agency RIA Novosti.

"Our targets related to enriching uranium are meeting our industrial and production needs... and those of our people," he was quoted as saying.

Asked whether Iran plans to enrich beyond 60 percent purity if the talks fail, he said "No".

Eslami was speaking ahead of the resumption on Monday of talks in Vienna aimed at reviving the 2015 Iran nuclear deal.

Iran's arch-rival Israel, which staunchly opposes the nuclear deal, had reportedly warned in November that the Islamic republic had taken the technical steps to prepare to enrich uranium to military-grade levels of around 90 percent.

Tehran insists its nuclear programme is for peaceful purposes.

The 2015 deal offered Iran relief from sanctions in return for curbs on its nuclear programme, but was derailed in 2018 when the US unilaterally withdrew under then president Donald Trump.

Other parties to the deal have taken part in the talks, but the United States has only engaged indirectly.

While the US and its Western allies have repeatedly called on Iran to offer assurances on its nuclear programme, Tehran has insisted sanctions must be lifted first.

US negotiator Rob Malley on Tuesday warned of a "period of escalating crisis" if diplomacy failed to restore the agreement.

In his interview with RIA Novosti, Eslami said Iran's nuclear activities comply with the regulations of the UN's International Atomic Energy Agency.

The IAEA recently expressed concerns over Iran's stockpile of highly-enriched uranium, however.