Khalilzad, who returned this week from nearly a month-long peace mission to South Asia and the Middle East, said that he had discussed conditions for the withdrawal of United States forces from Afghanistan with the Taliban, but there had been no agreement on this issue yet.
Pakistan's role in the peace negotiations is a delicate one, with Islamabad seeking to avoid demonstrating the kind of broad influence over the Taliban that Washington has long accused it of having.
US Special Representative for Afghanistan Reconciliation Zalmay Khalilzad will undertake an important visit to Pakistan before February 20 to finalise the peace accord with Taliban.
Khalilzad said an agreement was reached in principle with the Taliban "that no terrorist group, global terrorist group, or individuals would be able to use Afghanistan and the areas they control".
Led by Taliban's chief negotiator Mohammad Abbas Stanikzai, ten senior officials from the group this week travelled to Moscow for talks with Afghan politicians.
"We are after a peace agreement, not a withdrawal agreement".
He said that talks between two opposing powers are meant to achieve a mutual resolution to outstanding issues and the re-establishment of peace and stability.
The former president also said that it is the Afghan people, who should decide whether any foreign military bases should stay on the territory of Afghanistan.
Pakistan, long at odds with the United States over the war in Afghanistan, has begun to play a behind-the-scenes but central role in supporting US peace talks with the Afghan Taliban, including by facilitating travel to negotiations, USA officials and Taliban sources say.
Aladdin Grammys trailer gives first look at Will Smith as blue Genie
But the best bit comes right at the end as Aladdin , with Apu and a pixel-perfect CGI Magic Carpet right behind, rubs the magic lamp for the first time, unveiling the big attractive blue Smith.
The possibility of a unilateral U.S. withdrawal from Afghanistan has created a new wave of uncertainty in the region, "which poses yet another challenge to Pakistan", he warned.
"I think the message that I have here is a peace in Afghanistan will help our relations with Pakistan", he added.
The Afghans, he asserted, must sit across the table with each other and come to an agreement about their future of their country.
"We always would like Pakistan, like other countries to do more, but we appreciate what they have done so far and I have indicated and Secretary (of State), (Mike) Pompeo and the president that we want to have good relations with Pakistan, better relations with Pakistan", he said in response to a question.
"They (the Taliban) say they made a mistake in how they dealt with women the last time", Khalilzad said. "It will take time for the Taliban to appreciate that, but the message they have given to me is that they understand that they can not go back".
"They understand that they can not go back" to how things were, the United States negotiator said.
The roots of the conflict in Afghanistan is not only in Afghanistan but also in the broader region.
"But we don't have to wait until then for regional players to play a positive role".
"Pakistan has tried to facilitate talks between the Taliban and the United States and also favors inter-Afghan dialogue including between the Taliban and the (Afghan) government", he said.