Inspectors from the United Nations nuclear watchdog found uranium particles enriched up to 83.7% in Iran�s underground Fordo nuclear site, a report seen Tuesday by The Associated Press said.

The confidential quarterly report by the Vienna-based International Atomic Energy Agency distributed to member states likely will renew tensions between Iran and the West over its program.

The IAEA report, which only speaks about �particles,� suggests that Iran isn�t building a stockpile of uranium enriched above 60% � the level it has been enriching at from some time.

The IAEA report described inspectors discovering on Jan. 21 that the two cascades of IR-6 centrifuges in Fordo had been configured in a way �substantially different� to what had been previously declared. The IAEA took samples the following day, which showed particles up to 83.7% purity, the report said.

�Iran informed the agency that �unintended fluctuations� in enrichment levels may have occurred during the transition period,� the IAEA report said. �Discussions between the agency and Iran to clarify the matter are ongoing.�

Iranian officials could not be immediately reached for comment regarding the report, details of which had been circulating for about a week.

A spokesman for Iran�s civilian nuclear program, Behrouz Kamalvandi, sought last week to portray any detection of uranium particles enriched to that level as a momentary side effect of trying to reach a finished product of 60% purity. However, experts say such a great variance in the purity even at the atomic level would appear suspicious to inspectors.

Iran�s 2015 nuclear deal limited Tehran�s uranium enrichment to 3.67% � enough to fuel a nuclear power plant. The U.S.? unilateral withdraw from the accord in 2018 set in motion a series of attacks and escalations by Tehran over its program.

Iran has been producing uranium enriched to 60% purity � a level for which nonproliferation experts already say Tehran has no civilian use. Any accusation of enrichment higher than that further ratchets up tension over the program.

Uranium at 84% is nearly at weapons-grade levels of 90% � meaning any stockpile of that material could be quickly used to produce an atomic bomb if Iran chooses.

While the IAEA�s director-general has warned Iran now has enough uranium to produce �several� nuclear bombs if it chooses, it likely would take months more to build a weapon and potentially miniaturize it to put it on a missile. The U.S. intelligence community, as recently as this past weekend, has maintained its assessment that Iran isn�t pursuing an atomic bomb.

�To the best of our knowledge, we don�t believe that the supreme leader in Iran has yet made a decision to resume the weaponization program that we judge they suspended or stopped at the end of 2003,� CIA Director Williams Burns told CBS� �Face the Nation� program. �But the other two legs of the stool, meaning enrichment programs, they�ve obviously advanced very far.�

But Fordo, which sits under a mountain near the holy Shiite city of Qom, some 90 kilometers (55 miles) southwest of Tehran, remains a special concern for the international community. It is about the size of a football field, large enough to house 3,000 centrifuges, but small and hardened enough to lead U.S. officials to suspect it had a military purpose when they exposed the site publicly in 2009.

Any explanation from Iran, however, likely won�t be enough to satisfy Israel, Iran�s regional archrival. Already, Israel�s recently reinstalled Prime Minister Benjamin Netanyahu has threatened military actions against Tehran. And Israel and Iran have been engaged in a high-stakes shadow war across the wider Middle East since the nuclear deal�s collapse.

Meanwhile Tuesday, Germany�s foreign minister said both her country and Israel are worried about the allegations facing Iran over the reported 84% enriched uranium.

�We are united by concern about the nuclear escalation on Iran�s part and about the recent reports about the very high uranium enrichment,� Baerbock said. �There is no plausible civilian justification for such a high enrichment level.�

Speaking in Berlin, Israel�s visiting foreign minister, Eli Cohen, pointed to two options to deal with Iran � using a so-called �snapback� mechanism in the Security Council resolution that enshrined the 2015 nuclear deal to reimpose U.N. sanctions, and �to have a credible military option on the table as well.�

�From our intelligence and from our knowledge, this is the right time to work on these two specific steps,� he said.

(AP)