WASHINGTON, Feb. 5 (UPI) -- A White House spokesman said Tuesday President Obama takes the war against al-Qaida seriously, and drone strikes against the terrorist organization are legal.

White House press secretary Jay Carney was responding to a U.S. Justice Department memo, made public Tuesday, that says the United States can target its own citizens with drone strikes if they have recently been involved in violent attacks.


"I can just say that this president takes his responsibilities very seriously," Carney told reporters at the White House, "and first and foremost, that's his responsibility, to protect the United States and American citizens. He also takes his responsibility in conducting the war against al-Qaida as authorized by Congress in a way that is fully consistent with our Constitution and all the applicable laws."

He added: "We have acknowledged ... that sometimes we use remotely piloted aircraft to conduct targeted strikes against specific al-Qaida terrorists in order to prevent attacks on the United States and to save American lives. We conduct those strikes because they are necessary to mitigate ongoing actual threats, to stop plots, prevent future attacks and, again, save American lives. These strikes are legal, they are ethical and they are wise. The U.S. government takes great care in deciding to pursue an al-Qaida terrorist, to ensure precision and to avoid loss of innocent life."

NBC News reported Monday it had obtained a copy of the confidential 16-page memo. The case made for targeting U.S. citizens in countries such as Yemen is similar to, but goes beyond, the one laid out by Attorney General Eric Holder and other officials.

"The condition that an operational leader present an 'imminent' threat of violent attack against the United States does not require the United States to have clear evidence that a specific attack on U.S. persons and interests will take place in the immediate future," the memo said.

The undated memo, titled "Lawfulness of a Lethal Operation Directed Against a U.S. Citizen who is a Senior Operational Leader of Al-Qaida or An Associated Force," was given to members of the Senate and House intelligence committees. It said citizens can be considered imminent threats if they have recently been involved in violence and their views remain unchanged.

Such killings would be "a legitimate act of national self-defense that would not violate the assassination ban," the memo said.

Jameel Jaffer, deputy legal director of the American Civil Liberties Union, called the memo "a chilling document."

"Basically, it argues that the government has the right to carry out the extrajudicial killing of an American citizen," he added. "It recognizes some limits on the authority it sets out, but the limits are elastic and vaguely defined, and it's easy to see how they could be manipulated."