- Video report by ITV News Washington correspondent Robert Moore
President Donald Trump has said US troops do not need to remain in Syria.
It comes as the White House declared victory on Wednesday in the mission to defeat Islamic State militants there.
The Trump administration will withdraw all of the remaining American forces - approximately 2,000 American troops in Syria - according to a U.S. official.
Planning for the pullout has begun and troops will begin leaving as soon as possible, said the official, who spoke on the condition of anonymity.
President Trump said American forces no longer were needed in a country torn apart by long-running civil war.
He said on Twitter: "We have defeated ISIS in Syria, my only reason for being there during the Trump Presidency."
Trump has said since he was a presidential candidate, he wanted to bring back troops from the Middle East.
But officials have said in recent weeks that pockets of IS militants still remain.
U.S. policy has been that American forces would stay in place until the extremists were eradicated.
Trump's tweet followed a series of news reports that the U.S. was preparing to withdraw its troops from Syria.
Responding to the reports, Pentagon spokesman Col. Rob Manning said in a statement: "At this time, we continue to work by, with and through our partners in the region."
The U.S. first launched airstrikes against IS fighters in Syria in 2014.
In the years that followed, the U.S. began partnering with Syrian ground forces to fight the extremists.
The Pentagon recently said that IS now controls just 1% of the territory they originally held.