The United States has received word from public and private sources that Iran intends to release two American hikers who have been detained there for more than two years and convicted of spying, Secretary of State Hillary Clinton said today.

Clinton was optimistic when asked about recent delays that threaten their release, which some experts see as a power struggle between Iran’s President Mahmoud Ahmadinejad, who promised their release in an interview with NBC News’ Ann Curry on Tuesday, and Iran’s Justice Ministry, which is more influenced by the country’s supreme leader.

“We continue to hope that the two young Americans will be released as part of a humanitarian gesture by the Iranian government,” Clinton told reporters in San Francisco, where she and Defense Secretary Leon Panetta were meeting with their Australian counterparts.

She dismissed the delays, saying they’ve seen the same thing happen in other cases, as well.

“We have seen in the past some delays that have occurred after decisions were announced, so that at this point we are not at all concerned,” Clinton said, “because we have received word through a number of sources, publicly and privately, that the decision will be executed on and that we will see their return to their families.”

Clinton’s willingness to discuss the delicate subject of the hikers’ release – which appeared to be subject to internal power plays not only within Iran but also among Iran’s neighbors, which may seek to exert regional influence – was all the more striking because her spokesman was unwilling to even comment on the topic earlier in the week.

The country of Oman, which helped secure the release of a third hiker last year, sent a plane to Tehran this week and remains engaged in negotiations to free the two Americans. Iraqi leaders are also playing a role in negotiations, officials said on the condition of anonymity because of the sensitivity of the subject.

Swiss diplomats, who represent the United States in Tehran because it does not have an embassy there, are also involved.

Clinton refused, however, to guess why roadblocks have emerged.

“I’m not going to speculate on what the reasons are or what it might mean or might not mean, but I’m going to count on the Iranian government fulfilling the announcement that was made by the leadership of the country and hope that it can be expedited and we can see their release very soon,” she said.