US Defence Secretary Robert Gates has ordered an Army combat aviation brigade to Afghanistan as part of a build up of forces to counter a rising insurgency.
A senior defence official said on Friday the brigade of about 2800 soldiers will deploy to Afghanistan in the spring. It is equipped with both attack and transport helicopters.
The brigade will form part of an increase of some 20,000 troops requested by General David McKiernan to halt a growing insurgency by the Taliban and other groups, particularly in the east and south of Afghanistan.
The deployment has not yet been officially announced.
The United States has some 31,000 troops in Afghanistan. Some are operating as part of a 51,000-strong NATO force.