Briefing journalists on Khan's visit, the official also said that by extending an invitation to the Pakistani leader to visit the White House, the US has sent a message to Islamabad that the "door is open to repairing relations" and building an enduring partnership.
"By and large that security assistance is still suspended," said the official while responding to a question on the continued suspension of US security assistance to Pakistan, the Dawn reported.
The Trump administration suspended security assistance to Pakistan in January 2018, and this marks the first time a US official has discussed the possibility - even though remote - of removing that suspension if Pakistan takes certain measures.
"We will consider changing that suspension on certain items if Pakistan meets our security concerns both in Afghanistan, and with regard to some of the externally focus groups like Lashkar-e-Taiba and Jaish-e-Mohammed," the official told reporters during a conference call.
But so far, there "has been no change to that suspension and security assistance," the official added.
The official also said that to avail the opportunity for restoring a close relationship with Washington, Islamabad will have to "change its policies" towards terrorism and militancy.
Khan, who began his official engagements soon after his arrival on Saturday, goes to the White House on July 22 for an extensive three-hour visit, which includes a one-on-one meeting with US President Donald Trump and two meetings and a working lunch with the President's team.
The senior Trump administration official said that Trump will be most interested in encouraging Pakistan to assist in the Afghan peace process and he hopes that "the discussions will be productive".
The White House also sees the visit as an opportunity to incentivise Pakistan to use its leverage on the Taliban to advance the Afghan peace process.
"We see that this visit could incentivise Pakistan to continue down the path that they have started. They've facilitated contacts to Taliban and met some of our requests with regards to the Afghan peace process," the official said.
"We're at a critical juncture and we need to see more cooperation from Pakistan. They need to use their full leverage in this endeavour. And so, we see this visit as an opportunity to encourage them to do more," said the official.
Apparently, Afghanistan will be the main item on the US agenda and Washington seems clear that it needs Pakistan's support to achieve this objective.
"We are calling on Pakistan for assistance in moving the peace process forward," said the official, adding that the US "appreciates initial steps that Pakistan has taken to facilitate" the US-Taliban talks but at this "critical juncture in the peace process," it needs more support.
"We are asking Pakistan to pressure the Taliban into a permanent ceasefire and participation in intra-Afghan negotiations that would include the Afghan government," the official said.
The US would also ask Pakistan to take irreversible action against terrorist and militant groups, and to facilitate peace talks with the Taliban for an intra-Afghan dialogue, the official added.
For the US, the purpose of the visit "is to press for concrete cooperation from Pakistan to advance the Afghan peace process, and to encourage Pakistan to deepen and sustain its recent effort to crack down on terrorist and militants within its territory," the official said.
( With inputs from IANS )