Iran on Monday denied reports that it has enriched uranium up to 84 percent, just below the 90 percent needed to produce an atomic bomb, AFP reports.
On Sunday, Bloomberg News reported that inspectors of the International Atomic Energy Agency (IAEA) last week found uranium enriched to 84-percent purity in Iran.
Iran was last known to enrich up to 60 percent, while a 90-percent threshold is required for use in a weapon.
The Vienna-based IAEA later said it was in discussions with Tehran over the discovery.
The spokesman for the Atomic Energy Organization of Iran, Behruz Kamalvandi, on Monday described the Bloomberg report as "slander" and a "distortion of the facts", according to state news agency IRNA.
"The presence of a particle or particles of uranium above 60 percent in the enrichment process does not mean enrichment above 60 percent," he added.
A diplomat confirmed to AFP the 84 percent reported by Bloomberg, saying "the percentage is correct".
The IAEA is "giving Iran the opportunity to explain because it's apparently possible that there can be so-called 'spikes' of higher levels of enrichment," the diplomat added.
The discovery of the uranium comes as talks between Iran and world powers on reviving the 2015 Iran nuclear deal remain stalled.
Former US President Donald Trump withdrew from the 2015 Iran nuclear deal in 2018, and Iran responded by scaling back its compliance with the agreement.
The Biden administration sought to return to the deal and held indirect talks with Iran on a return to compliance.
Those talks have been stalled since September, when Iran announced it had submitted its comments to the US response to the European Union’s draft for reviving the 2015 Iran nuclear deal.
While Iran’s Foreign Ministry spokesperson said at the time that Iran’s response was prepared based on a constructive approach, a senior Biden administration official said the Iranian response "is not at all encouraging.”
A US official later said that the efforts to revive the 2015 Iran nuclear deal have “hit a wall” because of Iran's insistence on the closure of the UN nuclear watchdog's investigations.
Last month, IAEA chief Rafael Grossi warned that Tehran has amassed enough material for “several nuclear weapons”, though he added that Iran has not yet built a nuclear weapon and the West should redouble efforts to stop it from doing so.