International observers are watching Iran's rapidly expanding nuclear program with growing dismay as Tehran refuses to extend the pact and insists that its equipment continue to accurately document uranium-enrichment activities.

Iran claims they still store data from the International Atomic Energy Agency's monitoring equipment, but access to it will be closed until Iran completes the negotiation with world powers to reactivate the 2015 nuclear agreement, which would lift sanctions.

The deal, signed six years ago, limited Iran's nuclear activities. But after Trump re-imposed sanctions, Iran began to lift restrictions on its nuclear work, and now it has enough accumulated uranium to create warheads.

Although the Biden administration, along with China, France, Germany, Russia and the United Kingdom, have been trying to re-establish the 2015 treaty since April, the diplomats will not meet until August, when Iran's new president, Ebrahim Raisi, takes office.

Energy markets are following the discussions closely, anticipating growth in Iranian gas and oil exports if sanctions are lifted.

IAEA Director General Rafael Mariano Grossi spoke amid reports that US politicians will put pressure on Iran if negotiations to renew their agreement fail.

And according to Iran Foreign Minister Mohammad Javad Zarif, the country has more than tripled its uranium reserves, from 2.4 kg to 8.9 kg. This is technically indistinguishable from the material needed to create a nuclear weapon, since only 10-15 kilograms of highly enriched metal is required to produce it.

Iran has always said its nuclear program is for civilian use, but concerns in Western capitals and Israel over the possibility of making bombs pushed for an initial agreement.

Grossi said inspectors remain in Iranian territory, but their visits to nuclear facilities are limited. The IAEA investigation on traces of decades-old uranium found in several locations is still pending.

Failure to clarify the source of the material opens up another way for the United States to increase pressure on Iran.