Kabul, Afghanistan ? NATO will soon assume direct control over most military operations in Afghanistan, a move that will place 12,000 more U.S. troops under its authority, a spokesman for the alliance said Sunday.

The expansion will consolidate military command under top NATO leader British Lt. Gen. David Richards and phase out the role of U.S. Lt. Gen. Karl Eikenberry, whose troops will be transferred to NATO, said Mark Laity, an alliance spokesman in Kabul.

Of the 40,000 foreign troops in Afghanistan, only 8,000 U.S. troops will function outside NATO control: those tracking al-Qaida terrorists or involved in air operations, Laity said. The overall level of American forces will remain around 20,000.