Department of Justice says White House can use 'lethal force' on American citizens on US soil

The US government has the right to use military force on American citizens, even at home - but only in "extraordinary circumstances," the attorney general has stated in a letter to Senator Rand Paul.

Paul had threatened to filibuster the nomination of John Brennan, US President Barack Obama's pick for CIA director, "until [Obama] answers the question of whether or not the President can kill American citizens through the drone strike program on US soil."

Brennan was confirmed by the Senate Intelligence Committee on Tuesday, March 5, the same day Attorney General Eric Holder sent Paul the letter. Brennan now faces overall Senate approval.

The CIA boss nominee told Paul Tuesday that "the agency I have been nominated to lead does not conduct lethal operations inside the United States—nor does it have any authority to do so," advising the senator that the Justice Department would better suited to answer his inquiry regarding whether American citizens could be assassinated on home soil.

In Holder's Tuesday letter to Paul, he explains that as the country's leadership has never carried out a drone strike at home and has no plans to.

"The question you have posed is therefore entirely hypothetical, unlikely to occur, and one we hope no president will ever have to confront. It is possible, I suppose, to imagine an extraordinary circumstance in which it would be necessary and appropriate under the Constitution and applicable laws of the United States for the President to authorize the military to use lethal force within the territory of the United States."

For example, Holder says, "the president could conceivably have no choice but to authorize the military to use such force if necessary to protect the homeland in the circumstances like a catastrophic attack like the ones suffered on December 7, 1941, and September 11, 2001."

In a February Google+ Hangout, President Obama avoided the topic when asked to directly address whether he had the authority to assassinate Americans, leading observers to assume he did.