The International Atomic Energy Agency (IAEA) and Iran have failed to reach an agreement on a plan to investigate Iranian nuclear sites for allegations that the country is developing nuclear weapons. IAEA Deputy Director General for Safeguards Herman Nackaerts, who led a delegation from the U.N. nuclear watchdog to Iran, said the discussions “could not finalize” a document that “once agreed, should facilitate the resolution of outstanding issues regarding possible military dimensions of Iran’s nuclear program.” He declined to say whether any progress was made during negotiations. Nackaerts said the watchdog remains committed to dialogue, but added that no date had been agreed for further talks with the Iranian side. “We will work hard now to try and resolve the remaining differences, but time is needed to reflect on the way forward,” he said. “As on previous occasions, we were not granted access to Parchin,” said Nackaerts, referring to a nuclear site south of Tehran, which IAEA inspectors want to investigate for evidence of nuclear weapon tests. Iran’s ambassador to the IAEA Ali Asghar Soltanieh pointed on Wednesday to progress in talks with the nuclear watchdog, saying that “some differences were resolved and agreement on some issues in the modality was reached.” Western powers suspect Iran is working to develop nuclear weapons, while Tehran says the program is strictly for peaceful reasons.