WASHINGTON — The United States and Iran have agreed for the first time to one-on-one negotiations over Iran’s nuclear program, according to Obama administration officials, setting the stage for what could be a last-ditch diplomatic effort to avert a military strike on Iran.

Iranian officials have insisted that the talks wait until after the presidential election, a senior administration official said, telling their US counterparts that they want to know which American president they would be negotiating with.

News of the agreement — a result of intense, secret exchanges between US and Iranian officials that date almost to the beginning of President Barack Obama’s term — comes at a critical moment in the presidential contest, just two weeks before Election Day and a day before the final debate, which is to focus on national security and foreign policy.


It has the potential to help Obama make a case that he is nearing a diplomatic breakthrough in the decade-long effort by the world’s major powers to curb Tehran’s nuclear ambitions, but it could also pose a risk if Iran is seen as using the prospect of the direct talks to buy more time.

It is also far from clear that Obama’s opponent, Mitt Romney, would go through with the negotiation should he win election. Romney has repeatedly criticized the president as showing weakness toward Iran and failing to stand firmly with Israel against the Iranian nuclear threat.

Reports of the agreement have circulated among a small group of diplomats involved with Iran.

There is still a chance the initiative could fall through, even if Obama is re-elected. Iran has a long history of using the promise of diplomacy to ease international pressure on it. In this case, US officials said they were uncertain whether Iran’s opaque supreme leader, Ayatollah Ali Khamenei, had signed off. The US understandings have been reached with senior Iranian officials who report to him, an administration official said.

Even if the two sides sit down, US officials worry that Iran could prolong the negotiations to try to forestall military action and enable it to complete critical elements of its nuclear program, particularly at underground sites. Some US officials would like to limit the talks to Iran’s nuclear program, one official said, while Iran has indicated that it wants to broaden the agenda to include Syria, Bahrain and other issues that have bedeviled relations between Washington and Tehran since the American hostage crisis in 1979.


‘‘We’ve always seen the nuclear issue as independent,’’ the administration official said, speaking on condition of anonymity because of the delicacy of the matter. ‘‘We’re not going to allow them to draw a linkage.’’

The question of how best to deal with Iran has political ramifications for Romney as well. While he has accused Obama of weakness, he has given few specifics about what he would do differently.

Moreover, the prospect of one-on-one negotiations could put Romney in an awkward spot, since he has opposed allowing Iran to enrich uranium to any level — a concession that experts say is likely to figure in any deal on the nuclear program.

Beyond that, how Romney responds could signal how he would act if he becomes commander in chief. The danger of opposing such a diplomatic initiative is that it could make him look as if he is willing to risk another US war in the Middle East without exhausting alternatives.

‘’It would be unconscionable to go to war if we haven’t had such discussions,’’ said R. Nicholas Burns, who led negotiations with Tehran as undersecretary of state in the George W. Bush administration.

Iran’s nuclear program ‘‘is the most difficult national security issue facing the United States,’’ he said, adding: ‘‘While we should preserve the use of force as a last resort, negotiating first with Iran makes sense. What are we going to do instead? Drive straight into a brick wall called war in 2013, and not try to talk to them?’’


The administration, officials said, has begun an internal review among officials at the State Department, the White House and the Pentagon to determine the US negotiating stance, and what the United States would put in any offer. One option under consideration is ‘‘more for more’’ — more restrictions on Iran’s enrichment activities in return for more easing of sanctions.

Israeli officials, who have been pessimistic about diplomacy, say they are open to the notion of direct talks. ‘‘We don’t care how this happens, just as long as the Iranians cease enriching, give up their stockpiles of enriched uranium and forfeit their nuclear weapons program,’’ a senior Israeli diplomat said.

Direct talks would also have implications for an existing series of negotiations involving a coalition of major powers, including the United States. These countries have imposed sanctions to pressure Iran over its nuclear program, which Tehran insists is for peaceful purposes but which Israel and many in the West believe is aimed at producing a weapon.

Dennis B. Ross, who oversaw Iran policy for the White House until early 2012, says one reason direct talks would make sense after the election is that the current major-power negotiations are bogged down in incremental efforts, which may not achieve a solution in time to prevent a military strike.

Ross said the United States could make Iran an ‘‘endgame proposal,’’ under which Tehran would be allowed to maintain a civil nuclear power industry. Such a deal would resolve, in one stroke, issues like Iran’s enrichment of uranium and the monitoring of its nuclear facilities.

Within the administration, there is debate over just how much uranium the United States would allow Iran to enrich inside the country. Among those involved in the deliberations, an official said, are Secretary of State Hillary Rodham Clinton, two of her deputies — William J. Burns and Wendy Sherman — and key White House officials, including the national security adviser, Thomas E. Donilon, and two of his lieutenants, Denis R. McDonough and Gary Samore.

Iran’s capacity to enrich uranium bears on another key difference between Obama and Romney: whether to tolerate Iran’s enrichment program short of producing a nuclear weapon, as long as inspectors can keep a close eye on the program, vs. prohibiting it from enriching uranium at all. Obama administration officials say they could imagine some circumstances under which low-level enrichment in Iran might be permitted; Romney has said that would be too risky.

But Romney’s position has shifted back and forth. In September, he told ABC News that his ‘‘red line’’ on Iran was the same as Obama’s — that Iran may not have a nuclear weapon. But his campaign later edited its website to include the line, ‘‘Mitt Romney believes that it is unacceptable for Iran to possess nuclear weapons capability.’’ He repeated that in a speech at Virginia Military Institute this month.

For years, Iran has rejected one-on-one talks with the United States, reflecting what experts say are internal power struggles. A key tug of war is between President Mahmoud Ahmadinejad and Ali Larijani, Iran’s former nuclear negotiator and now the chairman of the Parliament.

Iran, which views its nuclear program as a vital national interest, has also shied away from direct negotiations because the ruling mullahs did not want to appear as if they were sitting down with a country they have long demonized as the Great Satan.

But economic pressure may be forcing their hand. In June, when the major powers met in Moscow, US officials say that Iran was desperate to stave off a crippling European oil embargo. After that failed, these officials now say, Iranian officials delivered a message to their US counterparts that Tehran would be willing to sit down for one-on-one talks, provided they took place after the elections.

At the United Nations in September, Ahmadinejad hinted as much, describing the reasoning to American journalists.

‘’Experience has shown that important and key decisions are not made in the US leading up to the national elections,’’ he said.