Iran says a report by the UN nuclear watchdog on traces of nuclear material found at three undeclared sites is unfair.
The report, issued on May 30, said the watchdog still had questions regarding nuclear material previously found at three sites -- Marivan, Varamin, and Turquzabad -- which had not been declared by Iran as having hosted nuclear activities.
The International Atomic Energy Agency (IAEA) said its long-running efforts to get Iranian officials to explain the presence of nuclear material at the sites had failed to provide answers.
Foreign Ministry spokesman Saeed Khatibzadeh told reporters on May 31 that the report “does not reflect the reality of the negotiations” between Iran and the IAEA.
"It's not a fair and balanced report," he said, adding that Iran expects it to be corrected.
Iran and the IAEA agreed in March on an approach for resolving the issue of the sites, one of the remaining obstacles to reviving the 2015 nuclear deal between Iran and world powers.
SEE ALSO: Award-Winning Iranian Actress Opens Up On 'Very Difficult' Exile, 'Problems' In HomelandTehran said it wanted the issue of uranium traces found at old but undeclared sites to be dropped and closed permanently.
The Joint Comprehensive Plan of Action, as it is formally known, gave Iran relief from crippling economic sanctions in exchange for curbs on its nuclear activities.
Then-U.S. President Donald Trump unilaterally pulled out of the pact in 2018 and reimposed sanctions, prompting Iran to begin backsliding on its nuclear commitments.
President Joe Biden's administration says it favors a return to the deal, including lifting key sanctions, but has rejected an Iranian demand to reverse the blacklisting of the Islamic Revolutionary Guards Corps as a terrorist organization.
State Department spokesman Ned Price said on May 31 that the United States had "full faith and confidence in the IAEA" and its chief, Rafael Grossi.
"Iran must fully cooperate with the IAEA without further delay," he told reporters in Washington.
The IAEA report also estimated that Iran's stockpile of enriched uranium has grown to more than 18 times the limit laid down in the nuclear deal and Iran is continuing its enrichment of uranium to levels higher than the limit permitted in the deal.
Western powers say Iran is getting closer to being able to quickly produce a nuclear bomb if it chose to, though Iran insists its nuclear program is peaceful.
The developments come as talks to revive the landmark 2015 nuclear deal between Iran and world powers remain deadlocked.