By Yeganeh Torbati
DUBAI (Reuters) - Iran has named a disarmament expert as its envoy to the U.N. nuclear watchdog, extending a reshuffle of top officials dealing with its disputed atomic program since new President Hassan Rouhani took office vowing to improve Iran's foreign relations.
Rouhani has yet to pick someone for arguably Iran's most important diplomatic post - chief nuclear negotiator with world powers - but the pragmatist tilt of his team so far points to a closer alignment of nuclear and foreign policy.
Reza Najafi, who has worked on disarmament issues within Iran's foreign ministry, will be its next ambassador to the International Atomic Energy Agency in Vienna, ISNA news agency said on Tuesday.
Najafi replaces Ali Asghar Soltanieh, who has been leading so far fruitless negotiations with the IAEA since early 2012 and was the ambassador during the hardline conservative tenure of President Mahmoud Ahmadinejad.
The U.N. agency wants to resume a long-stalled investigation into suspicions that Iran has carried out research relevant for nuclear weapons development, an allegation Tehran denies. Western diplomats accuse Iran of stonewalling the IAEA inquiry.
Rouhani, a relative moderate, has pledged to smooth Iran's relations with world powers to help ease stringent international sanctions imposed on the Islamic Republic over its nuclear program. Iran says it is enriching uranium only for civilian energy and medicine. The West suspects the program is covertly oriented towards developing a nuclear weapons capability.
Earlier this month Rouhani appointed former foreign minister Ali Akbar Salehi, seen as a relative pragmatist, to head Iran's atomic energy organization, a position he held before, replacing a conservative hardliner.
Vienna diplomats say the exit of Soltanieh, a strident conservative whose relations with the IAEA became tense, may be a further sign of Rouhani's desire for a fresh start with the outside world on nuclear issues.
Rouhani has vowed Iran will be more transparent and less confrontational in talks both with the IAEA and the big powers.
TONE NEW, SUBSTANCE NOT
But diplomats caution that it remains unclear whether Tehran's new tone will translate into substantive change, given that Rouhani has signaled no change in the Islamic Republic's insistence on the right to enrich uranium without restriction.
Little is known about Najafi's politics. But the state run English language Press TV said that as the head of Iran's atomic energy organization in 2010, Salehi tried to replace Soltanieh with Najafi at the IAEA, describing Najafi as "an expert in non-proliferation issues" who "deserves the post". But Soltanieh's term was ultimately extended.
Mark Fitzpatrick, director of non-proliferation and disarmament at the International Institute for Strategic Studies, said that when Najafi attended an IISS conference in 2010, he engaged with other participants during the breaks, listened well, asked good questions and defended Iran's interests but was not above correcting himself.
ISNA said Najafi was nominated by new Foreign Minister Mohammad Javad Zarif, a U.S.-educated former U.N. ambassador, for the IAEA post and Rouhani approved it.
For the pivotal post of chief nuclear negotiator, it is nearly certain that Rouhani will replace Saeed Jalili, a hardline ideologue of the Islamic Revolution who diplomats said spent more time lecturing than engaging with major powers.
A new head of the Supreme National Security Council, who has traditionally acted as chief nuclear negotiator, has yet to be appointed. The delay has raised speculation that Rouhani may be trying to win over power brokers in the clerical and security elites to shifting the job to the foreign ministry, a less hardline institution in Iran's multi-tiered power structure.
While the president can appoint a new head of the council, the fact it comprises representatives of government, parliament, judiciary, armed forces and clerical Supreme Leader Ayatollah Ali Khamenei makes it harder to settle on a negotiating line.
(Additional reporting by Fredrik Dahl in Vienna; Editing by Mark Heinrich)