Obama administration officials are downplaying  Defense Secretary Leon Panetta's comments that by late next year U.S. troops could  switch away from a combat role in Afghanistan to an advise-and-assist mission. 

Panetta's remarks caught members of Congress, as well as European and Afghan allies, by surprise, and some surmised that his comments were a  trial balloon for a strategy shift.

En route to a  meeting in Brussels with NATO defense ministers, Panetta said Wednesday that it was his hope that U.S. and NATO troops would transition to a training-and-advisory mission in Afghanistan in mid- to late-2013.  

"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." 

On Thursday, Obama administration  officials said Panetta's comments were in line with the agreement reached at the NATO Lisbon Summit that the alliance would transfer security responsibility to Afghan security forces by the end of 2014.

White House spokesman Jay Carney said Panetta was referring to "an assessment of what could happen within the context of the stated policy of NATO, which is to transfer the security lead to the Afghan security forces by 2014, and within that frame, within that timeline, the transition will take place."

Carney said "that it could happen that the transition to Afghan security lead could be moved up to 2013. But he was not making an announcement about a decision that had been made, simply about the consultations that would be taking place in Brussels and from Brussels forward to Chicago." 

In May, Chicago will host a summit for NATO heads of state.

CIA Director David Petraeus, the former top NATO commander, told Congress that Panetta's comments had been "over-analyzed."

Making "bunny ears" with his hands, Petraeus told the House Intelligence Committee "that the, quote, 'announcement,' the  conversation that Secretary Panetta had with some press on his plane  was more than a bit over-analyzed, shall we say."

Petraeus said that in order for NATO to reach the security transition by the end of 2014,  a wave of security transitions began in mid 2011.

"What Secretary Panetta was discussing was indeed this progressive transition," said Petraeus. "If you're going to have it completed totally by the end of 2014, obviously somewhere in 2013 you have had  to initiate that in all of the different locations so that you can  complete the remaining tasks.  And that was what he was talking about. "

He added, "The idea is that we gradually stop leading combat  operations, the Afghan forces gradually take the leadership, it's in a  successive series of transitions that take place."  

Pentagon spokesman Capt. John Kirby told reporters that Panetta was providing "what some of the thinking is" with respect to the road to the security transition by the end of 2014.   

"I think what he expressed reflects the view of many, not just himself, but many, leaders in the government that we believe hopefully we'll be in a position to begin the transition of the combat role prior to 2014," Kirby said.

He added, "There's absolutely no change to anybody's commitment to the principles of the Lisbon summit and ultimate transition by the end of 2014."

He said Panetta was indicating "the potential to be able to transition" the lead for combat operations in Afghanistan earlier than 2014.  Ultimately, he said no final decisions had yet been made by the alliance and that transition details would have to be decided at the Chicago Summit in May.

Panetta said Wednesday that 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."

Kirby reaffirmed that a gradual transition to an advisory role did not mean that U.S. and NATO troops would not be engaged in combat beyond that point. 

"The desire to look for opportunities to transition the lead for combat roles to Afghan national security forces prior to 2014 does not at all mean that we won't be engaged in combat operation through 2013 and into 2014, probably right up to the end," said Kirby.

The possibility of a switch next year to an advisory mission in Afghanistan is similar to how the Iraq withdrawal was conducted, and Panetta said as much to reporters on Wednesday.  

"Hopefully," he said, "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."

The defense secretary said Wednesday it was unclear how the shift would affect the pace of the withdrawal of U.S. troops from Afghanistan.   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."