"A small peace keeping group of about 200 will remain in Syria for period of time," White House press secretary Sarah Sanders said in a one-sentence statement.
Moreover, Graham said leaving a small force in Syria will serve as a check on Iranian ambitions and help ensure that IS fighters do not try to return.
"A safe zone in Syria made up of international forces is the best way to achieve our national security objectives of continuing to contain Iran, ensuring the enduring defeat of ISIS, protecting our Turkish allies, and securing the Turkish border with Syria," Graham said.
Trump's decision to pull 2,000 U.S. troops from Syria, which he initially said would be rapid but later slowed down, shocked U.S. allies and angered the Kurds in Syria, who are vulnerable to attack by Turkey. It also prompted the resignation of Defense Secretary Jim Mattis and drew criticism in Congress. Sen. Jack Reed, a Rhode Island Democrat, called the decision a "betrayal of our Kurdish partners."
The SDF is currently involved in a standoff over the final sliver of land held by IS in eastern Syria, close to the Iraq border.
Many believe the IS threat won't end with the pocket's recapture and an insurgency is underway. In a foreboding sign Thursday, the IS claimed responsibility for back-to-back suicide attacks that hit a village miles away, leaving more than a dozen people dead in a rare targeting of civilians.
It's unclear where the 200 remaining U.S. troops will be stationed.
The U.S. military has a limited network of bases inside Syria. Troops work mostly out of small camps in remote parts of the country's northeast.
Also, U.S. troops are among 200 to 300 coalition troops at a garrison in southern Syria known as al-Tanf, where they train and accompany local Syrian opposition forces on patrols to counter the IS group. Al-Tanf is on a vital road linking Iranian-backed forces from Tehran all the way to southern Lebanon — and Israel's doorstep.
Trump spoke Thursday with Turkey's President Recep Tayyip Erdogan.
"On Syria, the two presidents agreed to continue coordinating on the creation of a potential safe zone," the White House said in a statement about the call.
The White House also said acting Defense Secretary Patrick Shanahan and Chairman of the Joint Chiefs Gen. Joseph Dunford will be hosting their Turkish counterparts in Washington this week for further talks.
Associated Press writer Robert Burns in Washington contributed to this report.