VIENNA - The UN nuclear watchdog and Iran may be narrowing their differences on how to tackle concerns over Tehran's atomic ambitions, diplomatic sources said on Wednesday, suggesting a previously unexpected agreement was now not ruled out.

They spoke a day after the UN agency said there was a "good exchange of views" with Iran in a May 14-15 meeting which tested the Islamic state's readiness to address questions about suspected nuclear weapons-relevant research.

Iran's envoy said the talks were "fruitful" and both sides said they had agreed to meet again next week, two days before Tehran resumes negotiations with world powers concerned it may be seeking to develop atomic bomb capability.

Any sign that Tehran may be willing to step up cooperation with the International Atomic Energy Agency (IAEA) in its long-stalled investigation into possible military dimensions to Iran's nuclear program would be seen as positive by the West.

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