In the evening, Mr. Ghani and Mr. Abdullah were due to meet for face-to-face negotiations on the same subject, according to Muslim Saadat, a spokesman for Mr. Abdullah. Both men also met Tuesday night, he said.

Image The Afghan presidential candidate Ashraf Ghani, left, speaking at a news conference this month as his opponent, Abdullah Abdullah, looked on. Credit... Wakil Kohsar/Agence France-Presse — Getty Images

Announcing the candidate’s threatened withdrawal from the audit on Tuesday, his top auditor, Fazul Ahmad Manawi, said flatly, “We will not continue to be part of the process and any result coming out of it will not be acceptable to us and will have no credibility to us.”

That seemed to indicate Mr. Abdullah was backing out of the agreement Mr. Kerry brokered. But on Wednesday, the Abdullah campaign noticeably dialed back its language. “Until now Reform and Partnership has not decided to reject the agreement,” Mr. Saadat said, referring to the name of Mr. Abdullah’s campaign coalition. “But we will not attend the audit process any more since our demands are not met.”

That still left open the possibility that Mr. Abdullah would accept the audit result, provided that the two candidates could make a political deal.

Mr. Saadat said the candidate was willing to continue discussions on a national unity government. In such a government, Mr. Abdullah’s followers would be guaranteed senior positions, including the post of “chief executive” for the government. Defining the powers of that post has been the main sticking point between the two candidates, who have otherwise agreed on most issues, according to a senior American official, who spoke on the condition of anonymity because of the political sensitivity of the discussions.

The American official said that some supporters were less willing to make difficult compromises than the two candidates themselves, and said it was a positive sign that Mr. Abdullah and Mr. Ghani were meeting face to face in a cooperative manner.

“It’s entirely understandable that it would be difficult for groups of people who fought a very long, hard and at times nasty campaign and now they’re being asked to transition to cooperating together in a new government,” the American official said. “But the two of them have made that transition, the people around them have or are starting to.”