Nominee John Brennan, a strong supporter of drone attacks, will face questioning from Senators in a confirmation hearing Thursday. The nomination has also shed light on a previously secret drone base in Saudi Arabia, where Brennan served as CIA station chief.
Brennan was instrumental in negotiating with Riyadh over placing the drone base in the kingdom. The base has helped in hunting down al-Qaida terrorists in neighboring Yemen.
Critics say drone attacks are immoral and sometimes lead to civilian deaths. Pakistan has strongly criticized U.S. drone strikes.
Brennan has defended the use of drones as legal, ethical and highly effective. President Obama has said Brennan's counter-terrorism work has made it harder for al-Qaida to plan attacks against the United States.
White House spokesman Jay Carney said Tuesday the strikes are "wise" and necessary to "save American lives."