Attorney General Eric Holder said Monday that the US government can legally use lethal force against US citizens overseas involved in terrorist plots against the United States, dpa reported.
In a speech at Northwestern University Law School in Chicago, he said that if "capture is not feasible," the government can act to kill US citizens who "have decided to commit violent acts against their own country from abroad."
The action requires the government to determine through "thorough and careful review" that the suspect poses an "imminent threat" of attack against the country," Holder said.
"Any decision to use lethal force against a United States citizen - even one intent on murdering Americans and who has become an operational leader of al-Qaeda in a foreign land - is among the gravest that government leaders can face," he said.
Holder did not discuss the US drone strike in September in Yemen that killed militant Islamist preacher Anwar al-Awlaki, a US-born, US-Yemeni dual citizen believed to be the spiritual leader of the Yemeni branch of terrorist network al-Qaeda.
In another part of the speech, while discussing decisions to prosecute some al-Qaeda suspects in military commissions while sending others to civilian courts, Holder specified that al-Awlaki participated in ordering the attempted Christmas 2009 bombing of a US airline.
Hina Shamsi, a national security expert at the American Civil Liberties Union, called Holder's speech a "gesture" toward transparency.
"It is ultimately a defence of the government's chillingly broad claimed authority to conduct targeted killings of civilians, including American citizens, far from any battlefield without judicial review or public scrutiny," she said.
"Few things are as dangerous to American liberty as the proposition that the government should be able to kill citizens anywhere in the world on the basis of legal standards and evidence that are never submitted to a court, either before or after the fact."