The International Atomic Energy Agency, the UN's nuclear watchdog, on Sunday said it was in discussions with Iran after reports said that inspectors had found that the Islamic Republic had stepped up nuclear enrichment, AFP reported.
"The IAEA is aware of recent media reports relating to uranium enrichment levels in Iran," the Vienna-based agency wrote on Twitter.
It added it was "discussing with Iran the results of recent agency verification activities and will inform the IAEA Board of Governors as appropriate".
The comment came after Bloomberg News reported that inspectors of the 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 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.