Chief U. N. nuclear inspector says progress had been good during February 8-9 talks in Tehran but that much work remained in clarifying the related concerns.

" There are still a lot of outstanding issues, " Tero Varjoranta, deputy director general of the International Atomic Energy Agency(IAEA), said at Vienna airport after returning from the Iranian capital. " We will address them all in due course. "

Iran and six powers agreed late last year on an interim deal to curb Tehran ' s nuclear work in exchange for some easing of sanctions. Both sides will next week start talks on a long - term agreement.

Diplomats say the way the Iran - IAEA talks progresses will be important also for the outcome of the big powers ' diplomacy, which the West hopes will lead to a settlement.

" Continued progress on resolving PMD issues will go a long way to demonstrate to the international community that Iran is not pursuing nuclear weapons and is willing to come clean about its past activities, " Kelsey Davenport of the Arms Control Association, a U. S. research and advocacy group, said.

The IAEA said on Sunday that Iran had agreed to take seven new practical measures within three months under a November transparency deal with the IAEA meant to help allay concern about the nuclear program.