- International Atomic Energy Agency monitors will return in late February
- Both sides called the meetings a positive step
- Western powers believe Iran is developing nuclear weapons, a charge Tehran denies
- The watchdog agency wants to keep pushing on talks, its director says
The United Nations nuclear monitors plan to return to Iran at the end of the month after a positive assessment from both sides of the latest visit.
An International Atomic Energy Agency (IAEA) team spent three days in Tehran this week. Another meeting is planned for February 21-22.
"The agency is committed to intensifying dialogue," said Director General Yukiya Amano. "It remains essential to make progress on substantive issues."
The Iranian foreign minister called the talks "a positive forward step."
Ali Akbar Salehi told the semiofficial Fars News Agency that the IAEA "had some questions and we had very good meetings."
The team did not ask to inspect nuclear facilities, Salehi said.
"If they wanted an inspection, we were prepared to comply with their request," Salehi said.
The six-member delegation -- including chief inspector Herman Nackaerts and second-in-command Rafael Grossi -- arrived in Tehran shortly after the European Union imposed new sanctions on Iran aimed at cutting off funding to the Islamic republic's nuclear program.
Australia and the United States have also ramped up sanctions on Iran recently.
Western powers believe Tehran is trying to develop nuclear weapons, an assertion Iran denies.
Speaking Friday at the Davos Forum in Switzerland, Amano told reporters the visit was intended "to clarify the issues with possible military dimensions.
"We are not very sure whether Iran has declared everything and, therefore, we are not very sure that everything stays in peaceful purpose," he said. "In addition, we have information that Iran has engaged in activities related to the development of nuclear weapons. Therefore, we need to clarify."
Inspectors are in and out of the country regularly, an agency spokeswoman said Monday, but a high-level visit is more unusual.
Iran's President Mahmoud Ahmadinejad has said he is ready to discuss the program with a group of nations -- Great Britain, China, France, Germany, Russia and the United States -- that have held intermittent talks with Tehran.
The energy agency reported in November that it can no longer verify that the Iranian nuclear program remains peaceful, and Iran is under increasing international pressure to halt its nuclear fuel work.
Salehi told Fars Wednesday that Tehran will soon send a letter to the six world powers to reiterate its readiness for talks.
"We hope that the meeting will be held in a not far future," he said.