THE Pentagon is considering scaling back its massive build-up of drones, both to save money and adapt to changing security threats and an increased focus on Asia as the Afghanistan war winds down.

Air force leaders say the military may already have enough unmanned aircraft systems to wage the wars of the future and the Pentagon's shift to Asia will require a new mix of drones and other aircraft because countries in that region are better able to shoot down unmanned versions.

If the Pentagon does slow the building programme, ordered several years ago by then defence secretary Robert Gates, it will not affect the CIA drone strikes in Pakistan, Yemen and elsewhere against terror suspects.

Those strikes were brought centre stage last week during the confirmation hearing for White House counter-terror chief John Brennan, President Barack Obama's pick to lead the CIA.

General Mike Hostage, commander of Air Combat Command, said senior leaders were analysing the military's drone needs and discussions were beginning. But he said the current number patrolling the skies overseas may already be more than the service could afford to maintain.

The analysis began before Mr Brennan's confirmation hearings, where he was questioned sharply about the CIA's use of drones to kill terror suspects,