Former New Jersey Superior Court Judge Andrew Napolitano has blasted President Obama over the revelations that a drone strike he sanctioned killed hostages being held prisoner by al Qaeda in Pakistan.

The Libertarian pundit did not mince words, calling Obama’s actions “a war crime.”

“I condemn, in words as strong as anyone can muster, the idea that the president of the United States can be judge, jury and executioner for any American,” Napolitano said during an appearance on Special Report with Bret Baier.

“The Constitution expressly prohibits it, and we fought every single war against tyrants so that that type of unilateral power in the hands of one person, who now apparently delegates it to others, would ever come here.” the judge added.

Obama drone strike

“The president cannot summarily kill [Americans]. That’s a war crime!” Napolitano declared.

The President refused to take questions on the revelations Thursday, simply telling reporters that he took “full responsibility” for the drone strike, and “profoundly regret(s)” what happened.

The President apologised to the families of the victims, Warren Weinstein, an American doctor, and Giovanni Lo Porto, an Italian aid worker.

The hostages are just two of the innocent victims that have lost their lives to drone strikes which have killed untold numbers of civilians.

The Bureau of Investigative Journalism has calculated that between 421 and 960 civilians have been killed by drone strikes in Pakistan since 2002.

Last year the Watchdog also released figures indicating that close to two and a half thousand people have been killed by launches sanctioned by the Obama White House.

US drone strikes chart

The New York Times notes that the strikes are conducted not according to detailed intelligence, but rather constitute “an imperfect best guess” about who they are targeting.

“Every independent investigation of the strikes has found far more civilian casualties than administration officials admit.” the Times notes.

In regards to the latest revelations, Jameel Jaffer, deputy legal director of the American Civil Liberties Union, said “The US, quite literally, didn’t know who it was killing.”

Reporters with The Intercept have demanded to know when Obama will apologise for every other drone strike that has resulted in the deaths of innocent people.

“When asked by The Intercept if the president’s words meant there would be a policy change in how the U.S. deals with claims of civilian casualties resulting from counterterrorism operations, an administration official declined to comment.” the report notes.