A US official on thursday reported that the US president has decided to cut the amount of America troops in Afghanistan following his announcement to withdraw troops from Syria.
"That decision has been made. There will be a significant withdrawal," the official told AFP on condition of anonymity.
At the moment the United States has about 14,000 troops in Afghanistan working together with a NATO mission to support Afghan forces or in separate counter-terrorism operations.
Trump made this decision on Tuesday, the same time he told the Pentagon he want all US forces out of Syria.
US Defense Secretary Jim Mattis left his position earlier Thursday, saying his views are no longer in line with Trump's.
The president's twin foreign policy decisions on Syria and Afghanistan are nothing less than epic, and could begin to unspool a series of cascading and unpredictable events across the Middle East and in Afghanistan.
Mattis and other top military advisors last year persuaded Trump to commit thousands of new troops to Afghanistan, where the Taliban were slaughtering local forces in the thousands and making major gains.
Trump at the time said his instinct was to get out of Afghanistan.
The Wall Street Journal reported that more than 7,000 troops would be returning from Afghanistan.
The pullout comes as the US pushes for a peace deal with the Taliban.