Obama: Civilian drone deaths 'haunt us'

President Barack Obama has said that before approving any drone strike, there must be "near-certainty" civilians will not be hurt, in a major national security speech.

But, speaking at the National Defence University, Washington DC, the president said it was a "hard fact" that innocent lives had been lost.

Mr Obama said: "For me, and those in my chain of command, these deaths will haunt us as long as we live."