US Secretary of State Colin Powell said on Friday Washington had no way to force Iran to allow UN inspectors unrestricted access to suspected nuclear sites despite US doubts Tehran would come clean on its own. "I can't make sure it is going to happen," he told Reuters in an interview as he prepares to leave office. "You can't look in every cave that might be in Iran."
Powell also said Iran's agreement with Europeans last month to suspend some suspicious nuclear activities was inadequate, but said the international community must still press Iran to reveal the full extent of its weapons programme.
The Bush administration worries Iran may be developing a nuclear weapon at secret sites, where it may continue to work, while it has agreed to open other facilities to inspectors.
But Powell acknowledged Washington has failed to win international support, even from its major European allies, to demand unrestricted access.
"We have to remain uneasy about this (agreement) because it is still only a suspension. ... We really need an end to that program," he said.
"It is a question of whether or not the international community ... will be diligent and will be persistent in pressing the Iranians to give us full disclosure of their programs."
This week the UN nuclear watchdog rejected US demands that Iran be referred to the UN Security Council for possible economic sanctions and it passed an EU-sponsored resolution calling on Iran to freeze uranium enrichment activities. It noted the freeze was voluntary and non-binding.