The head of the U.S. military's special operations confirmed Friday, July 21 that the Central Intelligence Agency is shutting down its program to support rebels fighting against Syrian President Bashar al-Assad, AFP says.

General Tony Thomas denied that the four-year-old operation was brought to an end as a way to placate Russia and earn its support for a ceasefire in southwestern Syria.

It was a "tough, tough decision" but "absolutely not a sop to the Russians," Thomas said at a forum in Aspen, Colorado.

"It was, I think, based on an assessment of the nature of the program, what we're trying to accomplish, the viability of it going forward."

Asked about Thomas's comments, the CIA declined to comment.

On Wednesday the Washington Post reported the covert CIA program was being shut down.

The Post said President Donald Trump made the decision nearly a month ago after a meeting with CIA chief Mike Pompeo and National Security Advisor HR McMaster.

The Post said Trump made the decision in a effort to find ways to work with Russia in Syria, where Moscow supports Assad's government.