Talks between the U.N. nuclear watchdog and Iran on how to fully resume inspections in the Islamic Republic have made progress but time is running out, the watchdog's chief Rafael Grossi said Monday, adding he hoped they would conclude within days.

"Progress has been made. It is my sincere hope that within the next few days it will be possible to come to a successful conclusion of these discussions," Grossi told a meeting of the International Atomic Energy Agency's 35-nation Board of Governors, adding: "There is still time, but not much."