The IAEA extended a visit this week to Iran, where it was investigating the country's nuclear program. Talks last month in Tehran were described as amicable, though inspectors were denied access to the controversial Parchin military complex outside the nation's capital.
Ali Asghar Soltanieh, the Iranian ambassador to the IAEA, said another round of talks was set for mid-February in the Iranian capital, state-funded broadcaster Press TV reports.
"The talks between Iranian and IAEA negotiators were focused on finding a structured framework for mutual cooperation," the news agency stated.
Inspectors left Iran again this week without getting permission to visit the Parchin facility. Iranian officials this week brushed off allegations they were trying to hide controversial nuclear work there.
IAEA Deputy Director General Herman Nackaerts was quoted by the Christian Science Monitor as saying the two-day meetings in Tehran were "intensive."
"Differences remain, so we could not finalize the structured approach to resolve the outstanding issues regarding possible military dimensions of Iran's nuclear program," he said.
Iran is suspected of pursuing the technology needed to produce a nuclear weapon, an allegation the government denies. Multilateral talks with Western powers are tentatively scheduled for the end of January in Turkey.