Speaking at a news conference while in Brussels for a NATO meeting on, among other things, Afghanistan, Panetta declared as inaccurate media reports that the German defense minister indicated Panetta said the United States would keep 8,000-12,000 troops in Afghanistan after the military mission ends at the end of next year.
"We did discuss a range of options," Panetta said. "And what we discussed was a range of options that would be directed to the NATO force overall, which includes both the U.S. force contribution that we would make, plus what other NATO countries would contribute, as well. ... And we didn't define specifics on that. Frankly, that remains to be determined as we go forward with the planning process."
U.S. President Barack Obama has said the last combat troops will leave Afghanistan by Dec. 31, 2014, leaving the bulk of the country's security in the hands of the Afghans.
Afghan security forces are in the lead for "nearly 90 percent of combat operations," Panetta said. "And they are on track to step into the lead for all of these operations by this spring."
The United States will maintain a "strong presence" throughout the fighting season of 2013, he said.
"What we're looking at is probably a presence in excess of 60,000 during the fighting season through the final transition of tranche five, which would take place in August of 2013," Panetta said.
This fall, the number of combat troops would decrease to about 50,000 by November, and then to 34,000 by February of 2014, he said.
"We would maintain that number through the election in order to provide and assist the Afghans in providing sufficient security for the elections," Panetta said. "Once those elections were completed, we would then begin the final drawdown of our forces towards the end of 2014."
The alliance made a commitment after post-2014 "to ensure the success of this new mission and the long-term stability of Afghanistan," Panetta said. "We've made a commitment to a strong enduring presence and we intend to stand by that commitment."
Deep cuts in European defense spending and the "political gridlock" in the United States over its budget "is putting at risk our ability to effectively act together" to resolve challenges that are ahead.
"As I prepare to step down as secretary of defense, I do fear that the alliance will soon be, if it is not already, stretched too thin," Panetta said.