Iran's nuclear chief says even if talks to revive the 2015 deal fail and sanctions remain, Tehran will not exceed the 60 percent limit on uranium enrichment.

In an interview with the Russian news agency Sputnik on Saturday, Mohammad Eslami said that Iran does not intend to enrich uranium to higher levels no matter the results of negotiations aimed at salvaging the 2015 Joint Comprehensive Plan of Action (JCPOA).

"All our nuclear activities are carried out according to the agreements, statutes and regulations of the International Atomic Energy Agency", the AEOI chief stressed.

The JCPOA banned Iran from enriching uranium beyond 3.65 percent, but Tehran argues that because the US left the agreement and imposed sanctions, it is not bound by the limitation.

Tehran says it has increased its stockpile of 60% enriched uranium to 25 kilograms, potentially complicating efforts to revive the nuclear deal with world powers.

"So far we have produced 25 kilograms of 60% uranium, which, except for countries with nuclear weapons, no other country is able to produce," AEOI spokesman Behrouz Kamalvandi announced early in November.

The next round of Vienna talks to bring Iran and the US back to the deal is scheduled for Monday after seven rounds with no tangible results.

Western powers have expressed grave concern over the acceleration of uranium enrichment closer to weapons grade, saying Iran has "no credible civilian need for enrichment at this level".