Iran has accumulated enough enriched uranium to build a nuclear bomb, according to new findings from the United Nations atomic agency.
The International Atomic Energy Agency also said in a separate report that Iran has failed to provide credible explanations about nuclear material found at several sites in recent years, raising questions about the nature of its nuclear work.
The IAEA’s two reports could set the stage for a showdown at a meeting next week of its 35-nation board of governors, as Iran has demanded the watchdog wrap up its probe into uranium particles found at three undeclared locations in the country since 2019.
The U.N. nuclear watchdog said that Iran’s stockpile of uranium enriched to 60 percent had grown to 43.3 kilograms (95 pounds), which represented an increase of nearly 10 kilograms (22 pounds) compared to three months ago.
Experts said that the stockpile would provide roughly enough material for an atomic bomb if Iran took the additional step of enriching the uranium to 90 percent purity. Moving from 60 to 90 percent would not pose a technical challenge for Iran, according to arms control experts.
"Iran has now accumulated enough enriched uranium to be able to quickly produce more than a significant quantity of HEU (highly enriched uranium) for one bomb," said Daryl Kimball of the Arms Control Association think tank. "The time it would take them to do that can now be measured in days, not months or weeks."
The IAEA’s findings were sent to the agency’s members and obtained by NBC News and other news outlets.
The U.N. reports came as international talks aimed at reviving a 2015 nuclear deal with Iran have stalled. The accord imposed limits on Iran’s nuclear program in return for lifting economic sanctions. But then-President Donald Trump withdrew the United States from the deal in 2018 and reimposed sanctions.
Iran has since steadily blown past the deal’s restrictions on its nuclear activity, including limits on its use of advanced centrifuges and its stockpile of uranium.
The negotiations between world powers and Iran to salvage the 2015 deal have become bogged down over a demand by Tehran for the U.S. to lift sanctions on Iran’s Revolutionary Guard. Trump placed the organization on a terrorism blacklist.
The IAEA’s findings “underscore the urgency of restoring compliance with this deal,” Kimball said.
In its update on efforts to investigate the origin of the undeclared nuclear material found in Iran, the IAEA also said “Iran has not provided explanations that are technically credible in relation to the Agency’s findings at those locations.”
Iran also had not informed the U.N. agency of the current location of the nuclear material that was found or of equipment that had been contaminated with uranium particles, the IAEA said.
Iran was given “numerous opportunities” to account for the undeclared nuclear material, the agency said.
But Iran rejected the agency’s portrayal of its responses.
“Unfortunately, this report does not reflect the reality of the negotiations between Iran and the IAEA,” foreign ministry spokesman Saeed Khatibzadeh said Tuesday.
“It's not a fair and balanced report,” he told reporters. “We expect this path to be corrected.”
When contacted by NBC News, Iran’s U.N. mission referred to the comments from the foreign ministry, as well as Tehran’s envoy to the U.N. offices in Vienna.
Mohammad Reza Ghaebi, Iran’s acting ambassador to U.N. organizations in Vienna, said the IAEA’s report “is one-sided and fails to reflect Iran’s extensive cooperation with the IAEA.”