Top defense ministers in the alliance agreed to a new postwar mission in the country that will focus on training and advising the Afghan National Security Forces (ANSF) into 2015 and beyond, according to a NATO spokesman.
Gen. John Allen, current head of all U.S. forces in Afghanistan, is also expected to submit his postwar recommendations to the White House by 2013.
The NATO plan, Katz added, will not include combat operations by NATO forces but will be strictly focused on supporting ANSF units in country.
Alliance leaders agreed to funnel billions into the plan during NATO's defense ministers' conference in Brussels last week.
The White House and the Pentagon reached a tentative deal with Kabul in May on what the future U.S. presence would be in Afghanistan after the 2014 withdrawal.
The postwar American force will consist largely of U.S. special operations troops backed up by Afghan commando units, known as Kandaks, Allen said back in March.
Roughly 32,000 U.S. troops have already been pulled from the country, with the remaining 68,000 Americans drawing down over the next two years.
On the NATO side, alliance leaders will begin a "gradual adjustment" in the nearly 100,000-man force NATO currently has in Afghanistan, Katz said Monday.
Part of that adjustment will include pulling out all NATO-led provincial reconstruction teams along with front-line combat units by 2014, Katz said.
That reconstruction work, along with security operations, will be fully transitioned to the ANSF by then, he added. Afghan forces will be ready and able to handle both of those key missions in the country, Dominic Medley, spokesman for NATO's civilian force, said during the same briefing on Monday.
The alliance is confident that ANSF can take security reins, because those Afghan units are already shouldering nearly 80 percent of all joint Afghan-coalition operations in country, Medley said.
However, the NATO civilian spokesman noted that challenges still remain in completing that transition to the ANSF.
One huge challenge is dealing with the persistent rise of "insider" attacks by Afghan troops against U.S. and NATO forces.
Despite the best efforts by American and NATO commanders to stem the rise in such attacks, there is no possible way to completely prevent the attacks from happening, according to the top U.S. military officer.
"We can dramatically lower the numbers [of attacks] ... but we can't prevent it," Chairman of the Joint Chiefs of Staff Gen. Martin Dempsey said during a speech at the National Press Club last Wednesday.
To date, more than 51 coalition troops, mostly from the United States, have been killed at the hands of their Afghan partners in the past year.
While the attacks on American forces in Afghanistan will continue until the 2014 pullout deadline set by the White House, the four-star general was adamant the attacks would not throw the U.S. withdrawal strategy off track.