Iranhas slowed the expansion of its disputed uranium enrichment programme, the the International Atomic Energy Agency(IAEA) said today.
The Iranian shift was detected by IAEA inspectors last week after months in which Iran accelerated the installation of centrifuge machines that refine uranium, an effort Western leaders suspect is covertly meant to yield atomic bombs.
Iran has condemned two batches of limited UN Security Council sanctions adopted since December as illegal, insisting its programme aims only at generating electricity and vowing to press on with it.
IAEA director Mohamed ElBaradei said agency inspectors who just revisited Iran's vast underground enrichment plant at Natanz found it was scaling back its expansion in operations.
"We were there last week and we saw a slowing in the process of commissioning new cascades," Mr ElBaradei said, referring to interlinked networks of centrifuges that spin at high speeds to refine uranium into nuclear fuel.
"Without going into detail you could say that there is a fairly marked slowdown. It is not a full-size freeze, but it is a marked slowdown," he said after an IAEA governors meeting in Vienna.
Last month, he urged Iran to stop installing more centrifuges in return for a "time-out" in seeking further sanctions - an interim step to ease a standoff with world powers over their demand for a total enrichment shutdown.