Obama defends 'just' drones war

President Barack Obama has defended the use of drones in a "just war" of self-defence against deadly militants and a campaign that had made America safer.

In a wide-ranging speech on a programme shrouded in secrecy, he said there must be "near certainty" that no civilians would die in such strikes.

In a renewed push to shut Guantanamo Bay, he said he had lifted a moratorium on prisoner transfers to Yemen.

Mark Mardell reports.