The White House and Justice Department on Tuesday adamantly defended the administration’s authority to use unmanned drones to kill terror operatives — even if those operatives are U.S. citizens — following the release of a controversial memo on the program.

President Obama’s advisers are also trying to tamp down concerns about the targeted killings ahead of the confirmation hearing Thursday for CIA director nominee John Brennan — the counterterrorism adviser and drone-program supporter who has come under criticism from Democrats.

Pressed repeatedly about the complicated constitutional and legal questions raised by the targeted killing of Americans, White House Press Secretary Jay Carney said Tuesday that the president takes those issues “very seriously.”

But he noted that Al Qaeda is in a “state of war against us,” and defended what he described as “targeted strikes against specific Al Qaeda terrorists.”

“We conduct those strikes because they are necessary to mitigate ongoing actual threats, to stop plots, to prevent future attacks and to save American lives,” Carney said. “These strikes are legal, they are ethical and they are wise.”

Carney would not describe the legal criteria for ordering those drone strikes.

A Justice Department official, though, told Fox News there are at least three conditions that have to be met in order for a strike to be ordered — there has to be an “imminent” threat, the target has to have engaged in terrorist activities, and the target has to be unable to be captured.

Separately, Attorney General Eric Holder said Tuesday that the government is “confident that we’re doing so in a way that is consistent with federal and international law.”