Former CIA director nominee John Brennan today faced questioning at a Senate confirmation hearing about US drone strikes.
Mr Brennan said that drone attacks were only ever a last resort and refuted claims that strikes were used as punishments for past offences.
"Nothing could be further from the truth," he said.
"We only take such actions as a last resort to save lives when there's no other alternative to taking an action that's going to mitigate that threat."
He was also questioned about the use of water-boarding and said he found the practise "reprehensible and should never be done again"
"I had expressed my personal objections and views to some agency colleagues," he said.
"But I did not try to stop it, because it was something that was being done in a different part of the agency under the authority of others."
The hearing comes a day after the Justice Department agreed to send law makers documents explaining the legal rationale behind targeted killings of US citizens, thought to work with terrorist organisations.
The Justice Department confirmed the move after a memo, outlining some of the legal arguments, was leaked by NBC news earlier this week.
