President Barack Obama's administration is looking at easing the secrecy around the drone war against Al-Qaeda by shifting control for some air strikes from the CIA to the US military, officials say.

But the move would likely not apply to drone attacks in Pakistan, where most of the bombing raids take place.

And even if the policy change is carried out, Obama has no intention of abandoning a tactic that his advisers say has decimated the Al-Qaeda network.

Faced with growing calls in Congress for more oversight around the drone war, the administration is weighing the change partly to allay concerns from lawmakers and to put the air campaign on a more permanent legal footing, analysts said.

"There is serious consideration being given to moving some of these activities to" military control, a US official, who spoke on condition of anonymity, told AFP.

The administration believes the strikes are legal and effective but the change is "about transparency and the perceived legitimacy of the operations," the official said.

If the military were to take charge of some drone raids, that would subject the operations to more public scrutiny as the armed forces must operate under stricter legal guidelines and answer inquiries at public hearings in Congress.

Until now, the "targeted killings" with armed drones in Pakistan, Yemen or Somalia have been carried out under the CIA's authority as officially designated "covert" attacks, which allow officials to deny their existence.

But the drone strikes have become an open secret, and lawmakers and rights advocates have demanded the administration discuss the open-ended campaign publicly.

"If it's no longer possible with a straight face to deny that we're conducting these operations, then it makes sense to bring at least some of them out into the open, where the oversight is easier to conduct," said John Nagl, a fellow at the Center for a New American Security, a think tank with close ties to the Obama administration.

In Congress, there is growing interest "in regaining more of its authority over some of the the operations of the executive branch after a decade of war," he said.

Some lawmakers have called for creating a special court to oversee the drone strikes or vet "kill lists" of terror suspects, but the proposal appears unlikely to win approval in Congress.

In his State of the Union address, Obama promised to be "more transparent" about the program and told a recent online forum: "It is not sufficient for citizens to just take my word for it that we are doing the right thing."

Military leaders favor the possible move, which has been debated for months inside the administration, officials said.

The military's top brass "want this back" and believe the time has come for the CIA to stop running a large-scale air war against Al-Qaeda and instead focus on its main job of gathering intelligence, another official said.

The change likely would apply to drone bombing runs in Yemen, where the government publicly supports US assistance in fighting Al-Qaeda forces, and other countries ready to acknowledge an American role, officials said.

But the CIA is expected to retain authority for some secret strikes and to remain in charge of drone attacks in Pakistan's tribal areas, where the vast majority of the covert killings have taken place, officials said.

Out of an estimated 420 drone strikes carried out in Pakistan and Yemen since 2004, 350 have taken place in Pakistan, according to a tally by the independent New America Foundation.

The proposed policy shift would be welcomed by some lawmakers but fail to satisfy critics of "targeted killings," including rights groups and many foreign governments that view the attacks as illegal assassinations.

While senators have voiced concern about a small number of attacks that killed US citizens suspected of Al-Qaeda links, rights activists have condemned so-called "signature" strikes that target groups of unidentified militants.

Obama's pick to run the CIA, John Brennan, is seen as the architect of the drone war but is believed to support scaling back the spy agency's role, analysts said.

The White House favored a modest "reform" of the drone program partly to preempt any drastic action by Congress or courts that could jeopardize what it deems a successful tool in countering Al-Qaeda, said Micah Zenko, a fellow at the Council on Foreign Relations.

"They want to do this forever. And they know if they continue on the same path they're on, they'll have constraints imposed on them externally."