KABUL, Afghanistan - U.S. Defense Secretary Chuck Hagel arrived in the Afghan capital Saturday for an unannounced visit that comes as Washington and President Hamid Karzai remain at loggerheads over the terms of a plan that would keep American troops in the country beyond the end of next year.

Hagel is the latest senior U.S. official to visit Kabul in recent weeks, but unlike other dignitaries who have sought to coax Karzai into signing a bilateral security agreement, the secretary of defense opted to steer clear of the president.

That rare break with protocol seemed to signal a new strategy to end the impasse over the bilateral security agreement that could keep thousands of foreign troops in Afghanistan beyond 2014. U.S. officials appear to have concluded that ignoring Karzai could be more effective than continuing to beg him to ink the deal.

"We should not be in a position of having to coerce the leader of another country to have us be a presence in his country," Hagel said.

Conflicting reports

Hours after his arrival, Kabul was abuzz with conflicting news reports over whether Karzai and Hagel would meet for dinner. But Karzai's spokesman, Aimal Faizi, said the president never extended a formal dinner invitation to Hagel.

Hagel said he had not asked for a meeting with Karzai. "That was not the purpose of my trip. This trip is about the troops," he told reporters Saturday night.

Gen. Joseph Dunford Jr., the top U.S. commander in Afghanistan, said American officials have made their position abundantly clear to Karzai.

"All that needs to be said has been said," he said.

Hagel and Dunford declined to set a firm deadline for Karzai to sign the document, but they signaled that a NATO ministerial meeting scheduled for late February could mark a key turning point for allies that are contemplating contributing troops and money for post-2014 Afghanistan.

Dunford said the uncertainty about the international role here after next year is driving a flight of capital and a drop in real estate prices, as Afghans increasingly look to the coming months with dread.

On Saturday night, Hagel met with the Afghan defense minister, the head of the army and the deputy interior minister to reassure them that the United States is not on the brink of abandoning Afghanistan.

"We are continuing our support in every program," Hagel said. "We want the Afghans to succeed."

List of demands

Hagel's visit comes two days after the top U.S. diplomat overseeing Afghanistan policy reported having made little progress in a meeting with Karzai. James Dobbins, the U.S. special envoy for Afghanistan and Pakistan, said Karzai had not backed down from a list of demands that include the release of Afghans detained at the U.S. military prison in Guantanamo Bay, Cuba, and an end to U.S. airstrikes in his country. Karzai has cited recent U.S. strikes that led to civilian casualties as a reason for his reluctance to sign the deal.

"I have to say on the security agreement we didn't really make any progress," Dobbins told the Associated Press in an interview Thursday in Kabul. "It was sort of a restatement of the known positions."

A senior defense official said the Pentagon decided to forgo a meeting with Karzai because it has no reason to believe his position has changed.

Dobbins said Karzai is also intent on jump-starting peace talks with the Taliban as a precondition, a prospect Washington supports, albeit with deep skepticism.

"I did caution that, in the end, progress also depended on the Taliban, and our assessment was that they continue to be resistant," Dobbins said.

U.S. officials have said that failure to reach a deal soon could erode international support for Afghanistan during a crucial year that will include a presidential