Iran's deputy foreign minister pledged a "new approach" to resolving UN concerns about its nuclear programme as he began talks on Monday on easing a deadlock over an investigation into suspicions of illicit nuclear bomb research by Tehran.

Abbas Araqchi met UN nuclear watchdog chief Yukiya Amano in Vienna, the first such high-level encounter since Iran's election in June of a moderate president committed to improving its foreign relations after years of increasing confrontation.

"It is very important for all of us that we can show concrete progress," Amano said, sitting across a table from Araqchi at International Atomic Energy Agency headquarters in Vienna.

"We think this is the time to take a new approach to resolving (questions) between Iran and the IAEA and look to the future for further cooperation in order to ensure the peaceful nature of Iran's nuclear programme," Araqchi said. He gave no details.

The IAEA hopes to resume an investigation, long stalled by Iranian non-cooperation, into what it calls the "possible military dimensions" of the Islamic Republic's nuclear programme. Tehran says it is enriching uranium solely for electricity generation and medical treatments.

"It is peaceful and it will remain peaceful for ever," Araqchi said.  -Reuters