The U.N. nuclear agency chief on Monday announced new talks with Iran and urged it to sign a deal that would relaunch his long-stalled probe into suspicions that Tehran worked secretly on atomic arms.
For the first time, International Atomic Energy Agency head Yukiya Amano also said that Iran had demolished buildings and carried out other activities at a military facility that his agency believes was a site for such work.
Diplomats and officials accredited to the IAEA had spoken of similar work previously, describing it as an apparent attempt to clear the site of evidence of clandestine weapons-related work but confirmation by Amano lent weight to the suspicions.
Amano did not specify the focus of upcoming talks on Friday between officials from his agency and a senior Iranian envoy. But in the context of his remarks it was clear that IAEA negotiators would press Iranian officials to finalize an agreement on restarting his agency's investigation after a more than four-year pause.
Iran strenuously denies any interest in developing nuclear weapons, insisting that all of its atomic activities are under IAEA purview and meant purely to power reactors and for medical research.
But its critics note that the Islamic Republic refuses to stop enriching uranium, which can be turned from nuclear fuel into the fissile core of warheads, despite offers of reactor fuel from abroad and increasingly tough international sanctions.
In meetings with agency officials, Tehran also has stonewalled repeated IAEA requests for a resumption of its probe, dismissing intelligence cited by the agency of secret weapons work as fabricated by the United States and its allies and declaring the issue closed.
At stake in IAEA and other international efforts to engage the Islamic Republic is the threat an Iran armed with nuclear weapons could pose to its neighbors. The U.S. and Israel have indicated readiness to attack Iran if diplomacy and sanctions fail to curb its alleged nuclear program. Both suspect that Iran is aiming to build nuclear weapons, and Israel believes it would be a prime target.
Amano suggested his agency is not seeing everything it would like to, in opening comments to a meeting of the IAEA's 35-nation board.
"Iran is not providing the necessary cooperation to enable the agency to provide credible assurance about the absence of undeclared nuclear material and activities in Iran, and therefore to conclude that all nuclear material in Iran is in peaceful activities," he said.
Amano went to Tehran two weeks ago to try to wrap up a deal on restarting his probe and expressed confidence on his return that agreement was near, citing a senior Iranian official as telling him so. He invoked that promise in his comments to the IAEA's 35-nation governing board on Monday, telling them: "I was assured that agreement ... would be expedited."
Urging Iran to sign and implement the deal as soon as possible, he also appealed for quick access to a site at Iran's Parchin military site southeast of Tehran that the IAEA suspects is being cleansed of evidence of secret nuclear weapons-related testing.
The IAEA last week showed board member nations satellite images it said buttressed such suspicions. Diplomats at the closed meeting said the photos showed at least two buildings there razed and water streaming out of another structure suspected of hiding a metal chamber allegedly used to test explosives that could be used to set off a nuclear charge.
Commercial satellite images published subsequently by the Washington-based Institute for Science and International Security showed two buildings visible on earlier photos no longer standing.
"There are visible tracks made by heavy machinery used in the demolition process," said a commentary by the think tank accompanying the photos. "Heavy machinery tracks and extensive evidence of earth displacement is also visible throughout the interior as well as the exterior of the site's perimeter."
Amano told reporters the satellite images he has seen indicate "the use of water, demolishing buildings, removing fences and moving soil" -- his first public confirmation of what others say the photos show. He suggested -- without specifically saying so --that he feared the site was being cleansed ahead of any IAEA inspection.
"We have the general concern that these activities may hamper our future verification activities," at the site, he said. "Information that we have indicates that activities may have been undertaken related to the development of nuclear explosive devices and ... having access is very important to clarify this issue."
Separate from IAEA attempts to relaunch its probe, six world powers -- the United States, Russia, China, Britain, France and Germany -- are attempting to persuade Tehran to stop enriching uranium to a level that can be turned into warhead material more quickly than its low-enriched main stockpile. Their next meeting is in Moscow starting June 17.
Because all enriched uranium can be further processed to weapons-grade material, Iran's nuclear secrecy -- and its decision last year to start enrichment at a level closer to weapons-grade uranium at an underground bunker it says is safe from attack -- has fed worries that it could quickly "break out" a weapons program.