By LEE KEATH and MELANIE LIDMAN

CAIRO (AP) — Iranian, Egyptian and U.N. leaders met in Cairo on Monday to discuss Iran’s nuclear program after the U.N. nuclear watchdog agency in a confidential report said Iran is further increasing its stockpile of uranium enriched to near weapons-grade levels.

The report emerged amid U.S.-Iran talks aimed at attempting to limit Iran’s nuclear program in exchange for lifting some of the crushing economic sanctions that the U.S. has imposed on the Islamic Republic, which have strained relations for almost 50 years.

Rafael Mariano Grossi, director-general of the Vienna-based International Atomic Energy Agency, said the agency compiled its report, seen by The Associated Press over the weekend, because Iranian’s uranium enrichment is an ongoing concern for the IAEA’s board of governors.

Grossi said they hoped the report would provide “an incentive for a peaceful solution and a diplomatic solution.”

Iranian Foreign Minister Abbas Araghchi met with Grossi as well as Egyptian President Abdel Fattah el-Sissi and Egyptian Foreign Minister Badr Abdelatty.

IAEA expresses ‘serious concern’

The confidential IAEA report raised a warning, saying Iran is now “the only non-nuclear-weapon state to produce such material,” something the agency said was of “serious concern.”

The IAEA report said that Iran, as of May 17, had amassed 900.8 pounds of uranium enriched up to 60%. That is an increase of almost 50% since the IAEA’s last report in February. The 60% enriched material is a short, technical step away from weapons-grade levels of 90%.

Iran’s leadership has said it believes the IAEA report is politically motivated by Grossi’s hopes of becoming the next U.N. secretary-general.

Grossi is attempting to attract the votes of several members of the U.N. Security Council with the report, the head of Iran’s Atomic Energy Organization, Mohammad Eslami, told the official IRNA news agency late Sunday.

“He basically has chosen a political attitude, and this political attitude has led the environment to be more political rather that technical,” Eslami said.

Iranian deputy foreign minister Kazem Gharibabadi rejected many of the report’s findings. Gharibabadi noted on Sunday that out of the IAEA’s 682 inspections of 32 states, 493 were carried out in Iran alone.

“So long as a country’s nuclear activities are under the IAEA’s monitoring, there is no cause for concern,” he said. “The Islamic Republic of Iran is neither pursuing nuclear weapons nor does it possess any undeclared nuclear materials or activities.”

Questions about US transparency

Iran is concerned that the U.S. hasn’t provided enough transparency about what Iran can gain from the talks, Esmail Baghaei, Iran’s foreign ministry spokesperson, said on Monday.

“It must be crystal clear to us that how the unfair sanctions against the Iranian nation will be removed,” Baghaei said.

Omani Foreign Minister Badr al-Busaidi, who is mediating in the U.S.-Iran talks, visited Tehran on Saturday to present Washington’s latest proposal for ongoing discussions. The fifth round of talks between the U.S. and Iran concluded in Rome last week with “some but not conclusive progress,” al-Busaidi said at the time.

Araghchi said Monday that Iran will reply to the U.S. approach soon, but there will be no agreement unless Iran’s right to enrichment is respected.

“If the purpose of the talks is to attain trust that Islamic Republic of Iran will never go after nuclear weapons, I think an agreement is fully achievable,” Araghchi said. “But if there are unreasonable and unreal purposes, if the aim is depriving Iran from having peaceful activities, we will never accept any agreement.”

Lidman reported from Dubai, United Arab Emirates.