Afghan President Hamid Karzai (Aref Karimi/AFP/Getty Images)

The Obama administration is looking for ways to work around Afghan President Hamid Karzai’s new demands concerning a key security agreement with the United States, a senior U.S. official close to the negotiations said Wednesday.

“One of the things we’re trying to do quietly is design, engineer, imagine ways that we could get ourselves out of this fix,” the official said in an interview, speaking on the condition of anonymity because he was not authorized to describe the emerging strategy on the record. “One of those ways might be to find a mechanism, a technique where Karzai could abide by his loya jirga pledge not to sign it but still give us the document we need.”

Secretary of State John F. Kerry suggested this week that someone other than Karzai might sign the security deal. Possibilities include the top Afghan and U.S. defense officials, although U.S. officials played down that option after Kerry spoke.

But in Washington on Wednesday, Defense Secretary Chuck Hagel also suggested to reporters at the Pentagon that the signature of an Afghan leader other than Karzai might suffice.

“The issue of who has the authority to speak for the sovereign nation of Afghanistan, I suppose the lawyers can figure that out,” he said. “Whether it’s the minister of defense or the president, someone who has the authority to sign on behalf of Afghanistan, . . . I suspect that would fulfill the kind of commitment we need.”

Karzai’s spokesman, Aimal Faizi, on Wednesday dismissed suggestions that anyone besides the Afghan president could sign the agreement.

“You cannot get a bilateral agreement signed between two states if one of the states still has its conditions for its signing,” Faizi said. “It has to be signed by two sovereign states when it is mutually acceptable to both countries.”

Faizi reiterated that Karzai’s demands — including an end to U.S. military raids on Afghan homes, a reduction in American drone strikes and the launching of a U.S.-brokered peace process involving the Taliban — must be met before he will sign the agreement.

“We are certain that the U.S. can meet our conditions in practical terms within days or weeks,” Faizi said. “As long as Afghan demands are not accepted, President Karzai will not authorize any minister to sign it.”

Faizi’s comments coincided with a visit to Kabul by James F. Dobbins, the Obama administration’s special envoy for Afghanistan and Pakistan, for talks with senior Afghan officials. It was widely expected that Dobbins would meet with Karzai, although neither the U.S. Embassy in Kabul nor Faizi would comment on whether such a meeting took place Wednesday.

In the coming days, Karzai is scheduled to leave Afghanistan for talks with Indian Prime Minister Manmohan Singh. Karzai will also travel to Tehran, where he will meet with Iranian President Hassan Rouhani.

Iran’s government is calling on Karzai to reject the security agreement, and some analysts in Kabul say they think Iranian opposition is influencing his reluctance to sign it.

U.S. officials are talking to other Afghan officials apart from Karzai, the senior official said, and asking: “How can we help back Karzai off the ledge on this? And can we give him an out?”

Kerry joined other NATO foreign ministers here Wednesday in urging Afghanistan’s interior and foreign ministers to get the agreement signed quickly. A NATO plan to keep a small contingent of troops alongside U.S. forces in Afghanistan hinges on the same legal framework now in limbo.

The Afghan ministers told the NATO diplomats that they shared the sense of urgency and appeared optimistic that the deal could be signed soon, another U.S. official said without elaborating. The official, who was traveling with Kerry, spoke on the condition of anonymity to provide a summary of the closed-door session.

NATO countries and other nations that have pledged money or troops for the ongoing support of the Afghan military all face potential political, budgetary and logistical problems fulfilling those commitments if the U.S. security deal continues to languish, Kerry and other officials said during the two-day NATO meeting here.

U.S. officials working on the security agreement worry that a long delay or a failed agreement will give nations on the fence about an ongoing commitment in Afghanistan a reason to walk away, the senior official said.

That concern makes solving the Karzai puzzle even more pressing, he said.

“Our concern is that what might be best for Hamid Karzai and his legacy could well defeat the international effort to secure our gains in Afghanistan,” the official said.

U.S. officials failed to anticipate Karzai’s late opposition to signing the deal on what the Americans thought was an agreed-upon timeline. Now they are trying to better understand why Karzai changed his mind and how they can address at least some of his concerns and still get the deal signed quickly.

“We didn’t foresee all these antics, new conditions and all that,” the senior official said, but adding that it was anticipated that negotiations would be clouded by politics as the election approached. That meant getting the deal done in 2013, even though that has now left Karzai room to hold it hostage.

The second official later added that the United States considers the security agreement “a closed document” to which no further changes would be made, especially now that the Afghan tribal council, or loya jirga, has approved it.

The senior U.S. official said Karzai’s balk is an entirely political maneuver born of Karzai’s objectives for his final six months in office and beyond. Any solution to the impasse will have to take his political aims into account, including his desire for political influence now and after an Afghan election to replace him in April, the official said.

“He sees he has two levers to pull,” the official said. The bilateral security agreement, or BSA, is one. Holding out on the deal gives Karzai leverage with the United States that will evaporate later, the official said.

The other lever is Karzai’s influence over the scheduled presidential election, the official said. Being seen as a tough negotiator with the Americans gives Karzai continued credibility and sway as the vote approaches, the official said.

Craig reported from Kabul. Craig Whitlock in Washington contributed to this report.