WASHINGTON — Afghanistan’s national security adviser on Thursday accused the American special envoy, Zalmay Khalilzad, of seeking personal benefit by sidelining the Afghan government during peace talks with the Taliban in a broadside in which he raised concerns about “a deal that doesn’t end in peace.”

The comments by Hamdullah Mohib, a senior Afghan government official, displayed Kabul’s high distrust of the Taliban just as negotiators edged closer to an agreement on at least one major element of a final deal: preventing more terrorist attacks from being launched from Afghanistan.

Mr. Khalilzad was expected to brief military and diplomatic officials on the offer in meetings in Washington on Thursday and Friday. The Afghan government has not been part of the discussions because the Taliban refuses to meet with its representatives.

Speaking to a small group of journalists in Washington on Thursday, Mr. Mohib said that Mr. Khalilzad and other American diplomats involved in the talks had dribbled out only “bits and pieces” of the negotiations to the Afghan government.

