WASHINGTON — President Barack Obama will discuss the legality of his administration’s secret drone program and other counterterrorism practices during a speech Thursday, a White House official said.

Obama’s speech will be an attempt to fulfill his State of the Union pledge to be more “transparent” with the public about the controversial drone program that has become the centerpiece of the White House’s efforts to combat terrorism.

The official said Obama would also use Thursday’s address at the National Defense University to discuss efforts to close the Guantanamo Bay detention center. The president had vowed to renew those efforts despite being thwarted in his attempts to close the prison during his first term.

Obama had been ready to deliver the speech earlier this month, the official said, but it was delayed amid a series of distracting events. Among them: hunger strikes at Guantanamo and the Justice Department’s subpoena of phone records from journalists at The Associated Press.

Civil liberties groups and an unusual coalition of Democratic and Republican lawmakers have criticized the White House for keeping most details of the drone program secret. Particularly concerning for these critics has been the administration’s rare use of drones to kill American citizens overseas.

The administration is expected to increase its use of drones and other counterterrorism techniques as the war in Afghanistan winds to a close at the end of 2014 and the vast majority of U.S. troops return home.

The official was authorized to discuss the talk only on grounds of anonymity since Obama had yet to deliver it. Plans for the speech were first reported by The Washington Post.