"In terms of Al Tanf — that is, in terms of the drawdown plans — Al-Tanf would be the last place that we would withdraw from, and I think that’s something that has not been scheduled; it would be conditions-based," the official said.
“We are going to stick to our current policy [on Assad] while being the number one humanitarian donor to Syria," the official said. "We are not going to do anything in terms of reconstruction that would bolster the regime absent fairly significant political concessions on the part of Assad."
The official said it would be "very hard" for the United States to envision any future for Syria in which Assad plays a responsible role.
"We are supporting the UN [peace] process. We very much hope for a brighter future for the Syrian people, but it’s hard for us to envision that with Assad at the helm," the official added.
US officials have repeatedly called for Assad to resign, and Washington has supported a variety of militant groups that have fought to topple his government.
Trump announced in December that US forces would soon leave Syria and declared the Daesh terror group defeated in the country.
In June 2017, the US president ended a covert CIA program to arm and train militants fighting to oust Assad. Trump told the Wall Street Journal in an interview in July 2017 that he canceled the CIA program after learning that it had supplied weapons to the Al-Qaeda* terrorist group.
*Daesh (ISIS/ISIL/Islamic State) and Al-Qaeda are terrorist groups banned in US, Russia and many other countries.