President Barack Obamas administration has decided to give the Pentagon control of some drone operations against terrorism suspects overseas that are currently run by the CIA, several U.S. government sources said on Monday.

Obama has pledged more transparency on controversial counterterrorism programs, and giving the Pentagon the responsibility for part of the drone program could open it to greater congressional oversight.

Obama will make a speech on Thursday at the National Defense University in Washington that will include discussion of the governments use of drones as a counterterrorism tool. It is unclear whether he will announce the drone program shift in that speech or separately.

Four U.S. government sources told Reuters that the decision had been made to shift the CIAs drone operations to the Pentagon, and some of them said it would occur in stages.

Drone strikes in Yemen, where the U.S. military already conducts operations with Yemeni forces, would be run by the armed forces, officials said.

But for the time-being U.S. drone strikes in Pakistan would continue to be conducted by the CIA to keep the program covert and maintain deniability for both the United States and Pakistan, several sources said.

Ultimately, however, the administrations goal would be to transfer the Pakistan drone operations to the military, one U.S. official said on condition of anonymity.

The internal debate within the administration about whether to switch control of drone strikes to the military has been going on for months. Obama is under heightened pressure to show that his administration is transparent, after a series of scandals about civil liberties and allegations of government overreach broke last week.

A White House National Security Council spokeswoman and a CIA spokeswoman each declined comment.

DECISION AFTER MONTHS OF DEBATE

One of the reasons to make the shift is that it would help the CIA to return to more traditional spying operations and intelligence analysis, rather than paramilitary operations involving killing terrorism targets, officials have said.

The U.S. military is not engaged in ground combat in Pakistan, where the population in tribal areas has been angered by drone strikes and governments do not want to acknowledge that they allow U.S. unmanned aircraft to operate.

But in Yemen, the same sensitivities do not exist because the U.S. military is working with Yemeni forces in counterterrorism operations and so drone strikes in Yemen will shift to the Pentagon, two sources said.

There have been 355 drone strikes in Pakistan and 66 in Yemen, according to a widely cited drone attack database run by the New America Foundation think tank. (Database: natsec.newamerica.net/)

The United States has also carried out drone strikes in Afghanistan, Iraq, Libya and East Africa, some of them operated by the military.

The use of armed drones jumped in 2008 when President George W. Bush authorized the use of "signature" strikes, allowing the targeting of terrorism suspects based on behavior and other characteristics without knowing the targets identities.

Rosa Brooks, a New America Foundation fellow and Georgetown University law professor, said the problem with the targeted killing program was "an assertion by the executive branch that it has this essentially unconstrained and unreviewable power to kill people."

Brooks, who previously served at the Pentagon, said she hoped that Obama would publicly release the legal justifications and analysis for the targeted killings overseas, including of U.S. citizens.

"I would also like to see the president say that we will acknowledge all strikes, that we will publicly report on identities of who was targeted, at least after the fact," she said.