By Adrian Croft and David Alexander
BRUSSELS (Reuters) - NATO fleshed out plans on Wednesday for the smaller training and advisory mission it will leave in Afghanistan once it ends combat operations at the end of 2014, including which allies will take charge of the mission in each region of the country.
But the military alliance did not spell out how many troops would stay on, with several countries waiting for lead nation the United States to detail its commitment before making pledges of their own.
NATO-led forces are expected to cede the lead role for security across Afghanistan later this year to Afghan soldiers, 12 years after the U.S.-led overthrow of the Taliban government harboring Osama bin Laden, the al Qaeda leader who masterminded the September 11 attacks on U.S. cities.
NATO defense ministers endorsed an outline plan, known as a "concept of operations", on Wednesday for a smaller post-2014 mission that will give advice and training to Afghan security ministries and army and police commanders after most foreign combat troops leave Afghanistan by the end of 2014.
Military experts will now work out details of the new "Resolute Support" mission over the coming months, NATO chief Anders Fogh Rasmussen said at the end of a two-day meeting of alliance defense ministers.
U.S. Defense Secretary Chuck Hagel said the United States had committed to being the largest single contributor to the post-2014 mission and to being lead nation in the east and south of the country, the most volatile areas in recent years.
Germany had agreed to serve as lead nation in the north of Afghanistan and Italy in the west, he said. Turkey was "favorably considering" being the lead nation in Kabul for the new mission.
U.S. Marine Corps General Joseph Dunford, commander of international forces in Afghanistan, said specific troop numbers were not discussed.
"Now, over the next several months, and we believe in early fall, we will come back with a detailed operational plan that will talk about the specific resources required to execute the plan," he told reporters.
Dunford said on Tuesday that NATO was likely to wait until after this year's Afghan fighting season, which traditionally starts in spring when the snow recedes from the mountains, before deciding the size of the post-2014 force.
U.S. officials said in February that the alliance was considering keeping a residual force of 8,000 to 12,000 troops compared with about 100,000 now.
The White House has been discussing keeping 3,000 to 9,000 U.S. troops in Afghanistan as part of that, and President Barack Obama has come under increasing pressure to specify the number.
Most other NATO countries are waiting for the United States to take the lead on force size, and one NATO official acknowledged recently there was some impatience among other allies to hear what Washington will decide.
Germany is one of the few countries to decide on a specific commitment after 2014, announcing in April it wanted to keep between 600 and 800 soldiers in Afghanistan.
Afghan Defence Minister Bismillah Khan Mohammadi welcomed NATO's commitment to Afghanistan after 2014.
"This was of course a golden opportunity for Afghanistan and this was good news for the Afghan people and bad news for the enemies of the Afghan people," he told Reuters Television.
Mohammadi said the Afghan government would announce "towards the end of June" the final group of Afghan districts in which NATO-led troops will hand over lead security responsibilities to Afghan forces.
Dunford said that while the announcement of transition in this final group of districts would happen this month, it was "some months away" from actually being put into effect.
(Additional reporting by Francesco Guarascio; editing by Mike Collett-White)