Sen. Lindsey Graham, fresh off a trip to Afghanistan, said Sunday that he now believes some U.S. forces can begin withdrawing from the region next summer.

The South Carolina Republican, who previously suggested it would be a mistake to begin pulling troops out in July 2011, acknowledged that his thinking has evolved based on what he has witnessed on the ground. Speaking on CBS’ “Face the Nation,” Graham said he believes the Obama administration’s troop surge last year helped stabilize the region.

“I’ve seen progress I haven’t seen before, certain areas that could be transferred to Afghan control, and we could remove some troops without undermining the mission,” Graham said.

Still, Graham said all future decisions must be “conditions based” and that the U.S. will need “substantial troops” in Afghanistan well beyond July 2011. He said a lot needs to be done to get the country on solid footing, and the Afghan government “needs to do its part.”

“A lot needs to be done,” said Graham, a key member of the Senate Armed Services Committee.