Contrary to Trump's statements, Brett McGurk, the U.S. special envoy for the global coalition against ISIS, told a forum Tuesday that the U.S. mission in Syria was far from over.
"We are in Syria to fight ISIS. That is our mission, and our mission isn't over, and we are going to complete that mission," McGurk said.
Echoing those sentiments, Army Gen. Joseph Votel, who oversees U.S. forces in the Middle East as the head of Central Command, said that while the presence of ISIS in the region had diminished, "it is not gone."
Votel estimated that more than 90 percent of the terror group's territory had been recovered by U.S.-backed forces. He added that the next step for the approximately 2,000 U.S.troops in Syria would be to help stabilize the region.
"The hard part, I think, is in front of us, and that is stabilizing these areas, consolidating our gains, getting people back into their homes," Votel said alongside McGurk.
"There is a military role in this. Certainly in the stabilization phase."
The Pentagon did not immediately respond to CNBC's request for comment.
Earlier this week, Sen. Lindsey Graham, R-S.C., said Trump's proposal to pull U.S. troops from Syria would destabilize the region and prompt an ISIS resurgence.
"It'd be the single worst decision the president could make," Graham, a member of the Senate Armed Services Committee, said on "Fox News Sunday."
"This is a disaster in the making," Graham said, referencing Trump's off-the-cuff remarks last week at an Ohio event about infrastructure.
"We're knocking the hell out of ISIS," Trump said at the event Thursday. "We'll be coming out of Syria, like, very soon."
"Let the other people take care of it now. Very soon, very soon, we're coming out," Trump said. "We're going to get back to our country, where we belong, where we want to be."
Trump last year went through a similar wrenching debate over whether to withdraw U.S. forces from Afghanistan, ultimately agreeing to keep them there but only after repeatedly raising questions about why they should stay.
— Reuters contributed to this report.