President Barak Obama has confirmed US drone aircraft have struck Taliban and al-Qaeda targets in tribal areas in Pakistan. Until now, the operations have never been officially acknowledged.
During an online question and answer session on a Google social network, Mr Obama was asked whether he thought the programme was successful enough to justify the high numbers of civilian casualties.
Mr Obama responded by saying he wanted people to understand that drones had not caused a huge number of civilian casualties.
For the most part they have been very precise precision strikes against Al-Qaeda and their affiliates and we have been very careful about how they are deployed,. he told his questioner.
The BBC says more than 130,000 questions were submitted before the session - billed as an hour-long video hangout - began.
Six people from those were invited to join the President online for the event and were able to ask questions and seek follow-up answers from Mr Obama.
The session was also streamed live on the You Tube website.