After nine years of halting efforts to reach a peace deal with the Taliban, the draft framework, though preliminary, is the biggest tangible step toward ending a two-decade war that has cost tens of thousands of lives and profoundly changed American foreign policy.

A senior American official, speaking on condition of anonymity to discuss negotiations that were still continuing, said that the Taliban delegation had asked for time to confer with their leadership about the American insistence that the insurgents talk with the Afghan government and agree to a cease-fire as part of any finalized deal. The official said they had made it clear to the Taliban that all the issues discussed were “interconnected” as part of a “package deal” that he likened to a Russian nesting doll. The official’s account was supported by details that have been leaked by some Taliban and Western officials in recent days.

Although other Taliban sources said that more concrete details of an American troop withdrawal had already been agreed upon, American officials said on Monday that those details had not yet been hashed out.