The United States and its NATO partners will end their combat roles in Afghanistan in 2013 -- a year earlier than previously announced.
U.S. Defence Secretary Leon Panetta said that American troops will remain in the country through 2014, but only in a supporting role.
This switch to training and advising Afghan forces will occur in mid- to late-2013, Panetta told reporters in Brussels.
Despite pulling out last year, Canada still has more than 900 personnel in Afghanistan, who are taking part in training and other roles for Afghan forces.
Panetta's announcement seemed to come out of the blue for a top Canadian official. When asked about the U.S. decision on Wednesday afternoon, Canada's defence department parliamentary secretary said he wasn't aware of it.
"I haven't seen that," said Alexander on CTV's Power Play.
Still, Alexander said that the timing may be good news, as it shows that the U.S. and other key NATO allies believe that Afghanistan is nearly ready to fend for itself.
"That's still well over a year down the road. The U.S. is doing much more now than it was a couple of years ago, and its training mission alongside us will remain robust until the handover takes place," he said.
"I think we're still on track, and if it's a year earlier, that could be good news because it means that the Afghans are capable of looking after themselves."
Meanwhile, Panetta said that no decisions have been drawn up on how many American troops will stay in Afghanistan once the combat mission ends.
Panetta was in Brussels for a NATO meeting with other key allied officials to discuss Afghan issues, including Alexander's boss, Defence Minister Peter MacKay.
Earlier in the day, a leaked NATO report suggested that Pakistan is still supporting the Taliban in the decade-long war.
The report was gleaned from interviews with captured Taliban fighters.
"We've know that for a long time," said Alexander. "These are allegations that have been well-known to us for a long time."
The report also suggested that the captured militants were convinced that Afghanistan would be ruled by the Taliban again once NATO left.
But Alexander shrugged off that finding.
"I think there's a lot of reality to it, but it's not surprising. Taliban prisoners have always had this view," he said.
"These are typical views of the Taliban. The Taliban are being captured and killed on the battlefield now more than ever. They're a much weaker force in Kandahar and in many parts of Afghanistan."
The classified report also noted that captured prisoners felt that the Taliban was doing well on the battlefield.
"Their claims for how they're doing are clearly exaggerated. It's good to know how they are thinking, but it's not an objective assessment," Alexander said.