Kerry: U.S. can't 'walk away' from Afghanistan

The U.S. can't "walk away" from its effort in Afghanistan, Sen. John Kerry (D-Mass.) emphasized Friday.

Kerry, the chairman of the Senate Foreign Relations Committee, has been skeptical of recommendations for a troop surge in Afghanistan, but maintained that the U.S. cannot simply abandon its efforts in the reason.

"I don't think you can just pull out; I don't think anybody believes that," Kerry said during an appearance on the Don Imus show, broadcast by the Fox Business Network. "You can't just walk away for a lot of different reasons."

Kerry asserted that the U.S. needs to focus on keeping pressure on al-Qaeda wherever the terrorist group is, including Afghanistan.

"The Taliban has an ongoing relationship with al-Qaeda," he said. "It is the center of their efforts globally, even though they've moved more to Yemen and Somalia and other places -- where we don't, incidentally, have 68,000 troops or any troops."

"There's a lot of pressure on al-Qaeda right now, and we want to keep that on them," Kerry added.

Keeping pressure, Kerry indicated, includes not losing sight of significant challenges facing the U.S. in neighboring Pakistan.

"Be very careful about confusing a wholesale effort in Afghanistan with what we need to do in Pakistan," he explained. "One of the things I've pointed out: we've spent about $243 billion in Afghanistan cumulatively over the last eight years. We've spent maybe $10 billion less in Pakistan in that period of time. But Pakistan, everybody acknowledges, is of much more serious national security consequence to the United States."