WASHINGTON – President Obama's top foreign policy aides said Sunday that they planned to press Iran's newly elected president to resume the negotiations over his country's nuclear program that derailed in the spring.

But while the election of the new president, Hassan Rowhani, a former nuclear negotiator who is considered a moderate compared with the other candidates, was greeted by some administration officials as the best of all likely outcomes, they said it did not change the fact that only the country's supreme leader, Ayatollah Ali Khamenei, would make the final decision about any concessions to the West.

Even so, they said they wanted to test Rowhani quickly, noting that although he argued for a moderate tone in dealing with the United States and its allies when he was a negotiator, he also boasted in 2006 that Iran had used a previous suspension of nuclear enrichment to make major strides in building its nuclear infrastructure.

On the CBS program "Face the Nation" Sunday, Denis McDonough, Obama's chief of staff, said of Rowhani's election over the weekend: "I see it as a potentially hopeful sign. I think the question for us now is: If he is interested in, as he has said in his campaign events, mending his relations — Iran's relations with the rest of the world — there's an opportunity to do that." But McDonough said doing so would require Iran "to come clean on this illicit nuclear program."

Another senior administration official, speaking on the condition of anonymity, noted that for Rowhani, "wanting to end Iran's isolation is different from agreeing to move the nuclear program to a place where it would take them years to build a weapon."

Iran strategists critical of Obama

Many of the leading strategists on Iran from Obama's first term have become increasingly critical of the president's handling of the issue this year. Early optimism that Iranian negotiators were ready to discuss the outlines of a deal — one that would have frozen the most immediately worrisome elements of the country's nuclear program in return for an acknowledgment of the country's right to enrich uranium under a highly obtrusive inspection regime — faded in April, when the talks collapsed.

But Obama chose, after some internal debate, not to allow the breakdown in talks to become a crisis, partly because he was immersed in the debate over U.S. intervention in the Syrian civil war.

"There were a lot of distractions," said one former senior official who remains involved in the internal debates.

Last week, James B. Steinberg, a former deputy secretary of state in the Obama administration, co-wrote an op-ed article in the Washington Post arguing that "a sense of crisis is warranted" because Iran has used the first half of the year to develop two alternative pathways to potentially building a bomb.

One is through a new generation of centrifuges, not yet in full operation, that could sharply reduce the amount of time Iran would need to produce weapons-grade fuel. The second is the progress that the country has apparently made in building a heavy-water reactor, that could produce plutonium in coming years, the approach Pakistan is taking to modernize its nuclear weapons program.

Time running low

U.S. intelligence officials are concerned that once the facility is loaded with nuclear fuel, it could not be bombed without causing an environmental disaster. Intelligence officials have warned the White House that nuclear material could be put in the facility over the next year.

"The time is fast approaching when diplomacy will be of little or no value or credibility," Steinberg wrote with former Sen. Joseph I. Lieberman of Connecticut and Stephen Hadley, the former national security adviser to President George W. Bush. They urged the administration to "put forward a bold, comprehensive settlement offer that would be attractive to the Iranian people," something the administration has declined to do so far, and to make clear that the United States is "serious that all options, including the use of force" would be used if the offer was rejected.

Rowhani gave a glimpse of his views on negotiating strategy in a speech in 2004, which leaked out of Iran two years later. "While we were talking with the Europeans in Tehran," he recalled at the time, "we were installing equipment in parts of the facility in Isfahan," a major production site. "By creating a calm environment, we were able to complete the work in Isfahan."

He added a grace note that U.S. and Iranian officials often repeat today: "We do not have any trust in them," he said of the West. "Unfortunately, they do not trust us, either."