SAN FRANCISCO — US Secretary of State Hillary Clinton said Thursday that she was confident Iran would free two US hikers convicted of spying and rejected concerns about the delay in their release.

"At this point we are not at all concerned because we have received word through a number of sources, publicly and privately, that the decision will be executed... and that we will see their return to their families," she said.

Clinton, speaking to reporters after talks with Australia in San Francisco, said that it was not unusual for Iran to take time in implementing decisions and declined to speculate on whether there was a rift inside the regime.

"We have seen in the past some delays that have occurred after decisions were announced," Clinton said.

President Mahmoud Ahmadinejad had said that hikers Josh Fattal and Shane Bauer, who have been held in Iran for more than two years, would be released imminently.

But Iran's judiciary, which is dominated by ultra-conservatives, said that no decision has been taken.

Iran convicted the young Americans of spying but they insisted they were stopped as they hiked in the border area with Iraq.

A third hiker, Bauer's fiancee Sarah Shourd, was released on bail in September 2010.