American troops will still leave Afghanistan by the end of 2014, but Defense Secretary Leon Panetta laid out a plan today that by late next year could see U.S. and NATO troops in Afghanistan switching from a combat role to a training mission.

Traveling to a NATO defense ministers meeting in Brussels, Panetta provided reporters accompanying him with the clearest schedule yet for how the alliance plans to transition the lead for security in Afghanistan to Afghan security forces by the end of 2014.

 "Hopefully, by mid- to the latter part of 2013, we'll be able to make … a transition from a combat role to a training, advice and assist role," Panetta said, "which is basically fulfilling what Lisbon was all about." 

NATO leaders agreed at the 2010 NATO summit in Lisbon, Portugal, that Afghan security forces should take over security responsibility in Afghanistan by the end of 2014, bringing an end to a mission that has dragged on for more than a decade.

Panetta described 2013 as a "critical year" because it will see the end of the phased transition of the most difficult security areas to Afghan forces.  According to the defense secretary, 2014 would be about "consolidating the transition and making sure that those gains are in fact held."

Panetta said U.S. troops  could still see combat even after the shift to a train-and-assist mission in 2013. 

"It doesn't mean that we're not going to be combat-ready," he said. "We will be, because we always have to be in order to defend ourselves.  But we are going to be largely transitioning to a support role for the Afghan army as they take over these different areas in the future."

Next year's switch to a training mission in Afghanistan is similar to how the Iraq withdrawal was conducted, and Panetta said as much to reporters.  

"Hopefully, we could reach a point in the latter part of 2013 that we could make the same kind of transition we made in Iraq, from a combat role to a train-and-assist role," he said.

It was unclear how the shift would affect the pace of the withdrawal of U.S. troops from Afghanistan, Panetta said.   The 91,000 American troops in Afghanistan will be reduced to 68,000 by the end of September as part of the planned reduction of 33,000 surge troops President Obama sent in 2010.

"Frankly, we haven't made any decisions," about further troop withdrawals, said Panetta. "What I can say is that 2013 is a critical year and, therefore, will demand that we have a strong presence there in order to make sure that the gains that we've made up to that point are continued."

In December,  Gen. John Allen, the commander of U.S. and NATO forces in Afghanistan, told the Wall Street Journal that U.S. forces would  begin to be deployed this year with Afghan units as advisers and trainers as the Afghan forces began to take the lead militarily.   

Panetta said it was important that NATO stick to the 2014 withdrawal timetable.

"The Lisbon strategy basically said that we ultimately are in a process where we will withdraw our forces by the end of 2014," he said. "And I think we ought to stick with that."

France broke with the 2014 timetable last week when French President Nicolas Sarkozy announced that French combat troops would speed up their withdrawal and be out of Afghanistan by the end of 2013.  Sarkozy made his decision after a deadly attack by an Afghan soldier killed four French troops.  A small contingent of French trainers would remain in Afghanistan in 2014.

Chicago will host a NATO leaders' summit in May. That, presumably, would be the venue to formalize the timetable laid out by Panetta.

Republican members of Congress reacted negatively to the plan outlined by Panetta. 

House Armed Services Committee Chairman Rep. Howard "Buck" McKeon, R-Calif., labeled the change in mission "premature" and said in a statement that he "has not seen a single assessment by our commanders that indicates they have any confidence in such a swift transition."

He added that the administration should "justify this change in strategy to Congress before announcing it publicly."

Sen. John McCain, R-Ariz., the ranking Republican on the Senate Armed Services Committee, said describing the switch "sends exactly the wrong signal to our friends and enemies in this conflict.  It continues the administration's misguided policy of publicly forecasting its plans to withdraw from Afghanistan."