The chief of the United Nations nuclear watchdog agency said Tehran may have destroyed or hidden aspects of its much-debated nuclear program, and that recent negotiations have been unproductive.
Yukiya Amano, head of the International Atomic Energy Agency (IAEA) said Monday that "very extensive" engineering work at Iran's Parchin military base may have made inspecting the base pointless, though he still stopped short of withdrawing the agency's request for access.
"It may no longer be possible to detect anything," Amano told reporters at the IAEA headquarters in Vienna, adding that he wished "we had had the opportunity to have access to Parchin much earlier."
IAEA inspectors have not had access to Parchin since 2011, with Iran claiming that the UN agency has no need to visit the base since it's not a nuclear facility. However, the IAEA alleges that satellite images show activity suggesting the large-scale removal of soil, asphalting and breakdown of infrastructure, which could indicate a cover-up.
But Amano added: "I still believe it is necessary for us to have access to the site because by visiting the site we can learn a lot of things. Also we should not forget it is not only the site that we have questions [about]."
In related news on Monday, the US increased economic pressure on Tehran with sanctions targeting Iran's auto-sector and the rial, its currency, which has already lost much of its value since late 2011.
"The objective is to take aim at the rial and to make it as unusable a currency as possible, which is all part and parcel of our efforts to apply significant financial pressure on the government of Iran," an official, who spoke on condition of anonymity, told Reuters on a conference call.
The new sanctions go into effect on July 1.