By Maria Golovnina and Fredrik Dahl
LONDON/VIENNA (Reuters) - The U.N. nuclear chief dismissed Iran's allegation his agency may have been infiltrated by saboteurs and voiced concern about "intensive activities" at the Parchin military installation that his inspectors want to examine.
Years of diplomacy and sanctions have failed to resolve a stand-off between the West and Iran over its nuclear program, raising fears of last-resort Israeli military action and a new Middle East war destabilizing to the global economy.
Yukiya Amano, who is seeking to unblock a long-stalled investigation into suspected nuclear weapons research in the Islamic state, also said on Wednesday he hoped for a new high-level meeting with Tehran soon but no date had been set.
His agency's relations with Iran have become testy in recent months. Iran's nuclear energy chief said in Vienna last month the U.N. International Atomic Energy Agency may have been infiltrated by "terrorists and saboteurs".
Western diplomats have dismissed the Iranian allegations against the IAEA as a maneuver to divert attention from Tehran's stonewalling of its inquiry.
"Sometimes it is not useful to dignify these claims by providing an official answer," Amano said in London when asked about the saboteur accusation - apparently based on Iranian perceptions that inspectors pass on their findings to Western intelligence agencies.
But, the veteran Japanese diplomat said, "this is baseless ... We are not involved in these activities."
His comments about Parchin will likely reinforce suspicions among Western diplomats, first voiced early this year, that Iran is still trying to remove any evidence of illicit nuclear-related activity at the facility southeast of Tehran.
Asked whether Iran was continuing to dismantle a site that is part of the Parchin complex, which U.N. inspectors can now only monitor via satellite imagery, Amano told Reuters: "Yes."
Addressing London's Chatham House think-tank, he later said: "They are undertaking quite intensive activities at Parchin."
Iran has dismissed allegations of a cover-up aired about Parchin, which it says is a conventional military facility.
The U.N. nuclear agency believes Iran, possibly a decade ago, may have carried out explosives tests relevant for nuclear weapons development in a steel chamber at Parchin.
IRAN UNDER PRESSURE
In Vienna, a Western diplomat said the suspected clean-up work at Parchin "hasn't abated".
Amano said in June satellite images indicated buildings were being demolished and soil removed at Parchin.
A U.S.-based think-tank published new satellite imagery of Parchin on Wednesday which it said showed "a further phase of activity" and that Iran appeared to be removing tarpaulin covers placed earlier on two buildings at the site, including one where the suspected tests may have taken place.
"Alterations to the site for all intents and purposes have to be seen as clean-up operations with the intent to degrade or eliminate the IAEA's ability to examine the site," the Institute for Science and International Security said.
The IAEA, a Vienna-based U.N. agency tasked with preventing the spread of nuclear arms in the world, is trying to revive its bomb research investigation that has made no substantive headway for four years because of Iranian non-cooperation.
Amano said the IAEA was committed to dialogue with the Islamic Republic, which says its nuclear program is entirely peaceful and only aimed at producing electricity.
"We have offered that we are willing to meet with them in the very near future ... That (will) be a high-level meeting and I hope we can have a meeting quite soon," he said.
A senior IAEA team has held a series of meetings with Iran since January, but they have yet to yield concrete results. The last round of discussions took place in August.
Another Western diplomat in the Austrian capital said the IAEA had "really been pushing Iran to set a date" for a new meeting, but Tehran had so far declined to do so. "The delay is coming from the Iranian side," the envoy said.
Iran denies Western accusations that it is seeking to develop the capability to make nuclear bombs. But its refusal to curb activity that can have both civilian and military purposes has drawn increasingly tough Western sanctions.
(Editing by Andrew Heavens)