By Fredrik Dahl
VIENNA (Reuters) - World powers will refrain from raising pressure on Iran at a U.N. nuclear meeting next week to give its new moderate president time to show he is serious about moves to reduce tensions over its atomic activity, Western diplomats say.
But they stressed that concrete progress is needed soon in the dispute: talks on September 27 between Iran and U.N. nuclear inspectors will be scrutinized for any sign that the new Iranian government will be more transparent and less confrontational as President Hassan Rouhani has pledged.
Iran says its nuclear energy program is for electricity generation and medical uses only, rejecting Western accusations it is covertly trying to develop the capability to make bombs.
The June election of Rouhani as president, succeeding conservative hardliner Mahmoud Ahmadinejad, has stirred hopes that it may be possible to resolve a decade-old dispute and avert the threat of a new Middle East war.
Rouhani, keen to secure a relaxation of harsh international sanctions on Iran, has signaled readiness to be more open about Iranian nuclear activities in return for the acceptance of Tehran's right to enrich uranium for peaceful purposes.
The September 9-13 meeting of the 35-nation board of the International Atomic Energy Agency (IAEA), one of four annually, will be its first since Rouhani's rise.
During Ahmadinejad's eight-year tenure, the board passed six resolutions rebuking Iran over its nuclear defiance and evasions of IAEA scrutiny, demanding a suspension of enrichment and full cooperation with IAEA inspectors, and clearing the way to successive batches of United Nations sanctions since 2006.
"There has definitely been a change in tone from the Iranian government which we recognize and welcome," a Western envoy said, speaking ahead of next week's governing board meeting.
"We have to give them at least the time to translate their words into action," the envoy added, noting there were no plans - unlike previous board meetings - to push for a resolution to chide Iran over its refusal to curb sensitive atomic activity.
So far there is no clear indication of Iran slowing its nuclear campaign. An IAEA report last week showed Iran preparing to test 1,000 advanced uranium enrichment centrifuges, enabling it to produce more quickly nuclear material that can have both military and civilian applications.
WEST WANTS MORE THAN "WORDS"
"We expect and hope to see more than words" from Iran, the senior diplomat said, echoing the views of other Western officials in Vienna, where the IAEA is based.
The calibrated Western restraint towards Iran at this board meeting contrasts with U.S. preparations for punitive air strikes on Tehran's closest regional ally, Syria, over a poison gas attack in its civil war that killed hundreds of civilians.
There are concerns U.S. action against Syrian President Bashar al-Assad could give hawks in Iran's multi-tiered power structure an opening to scuttle Rouhani's diplomacy.
Western envoys at the IAEA declined to comment on suggestions that another reason for easing off on Iran at the board meeting was a wish not to make Rouhani more vulnerable to hardliners at home if U.S. strikes against Syria go ahead.
SEPT. 27 IAEA-IRAN TALKS
The United States late last year warned it may ask the IAEA governors to report Iran to the U.N. Security Council if it kept stonewalling the U.N. agency's investigation into suspected atomic bomb research by Tehran.
Iran - which was first reported to the U.N. Security Council over its nuclear program by the IAEA board in 2006 and then was hit by U.N. sanctions - says allegations of such covert activities are based on forged intelligence from its foes.
Another senior Western diplomat said the Iran-IAEA meeting later this month would be an opportunity for Iran to convey a "different message" to the outside world. "September 27 is going to a be very interesting day," the envoy said.
The two sides have held 10 rounds of negotiations since early 2012 in an attempt by the IAEA to resume its inquiry.
The talks have failed to yield results but Iran last month announced it would replace the envoy who has led the country's team in the discussions, in a possible sign of its desire for a new start after Rouhani's election.
"One would hope that by November there is some greater clarity on what Iran is prepared to do to resolve the issues that have been put on the table," the second Western diplomat said, referring to the next quarterly meeting of the IAEA board.
The Iran-IAEA talks are separate, but still closely linked, to negotiations between six major powers - the United States, Russia, China, Britain, France and Germany - and Iran aimed at finding a broader diplomatic solution to the nuclear dispute.
(Editing by Mark Heinrich)