President Obama says an exit plan is key to a comprehensive strategy in Afghanistan.

He hopes his strategy will help prevent another attack on the U.S.

The President calls the country a "tough nut to crack" with issues that commanders on the ground judge to be more difficult to fix than in Iraq.

Obama wants to send 17,000 more American troops into Afghanistan.

But the president also says the U.S. needs to pursue more than just a military approach.

Obama is planning on filling in the details of his comprehensive strategy later this week.