U.S. Secretary of Defense Robert Gates has designated a combat aviation brigade to be deployed to Afghanistan next spring, the Washington Post reported on its website on Friday.

The order, involving some 2,800 troops armed with attack and transport helicopters, is part of an ongoing military buildup in Afghanistan which will add a total of 20,000 troops to the existing U.S. presence in that central Asian nation, according to the report.

The buildup was requested by David McKiernan, the U.S. general commanding U.S. and NATO troops in Afghanistan, and was approved by Gates.

President-elect Barack Obama has called for sending more troops to Afghanistan to counter a resurging Taliban remnant, and has made it a campaign promise.

There are currently 32,000 US troops in Afghanistan, 14,000 of whom are part of the 51,000-strong NATO-led International Security Assistance Force.