President Barack Obama said Thursday that he will engage Congress in exploring a number of options for increased oversight of lethal drone strikes outside of war zones like Afghanistan.

The official U.S. figures of number of strikes and estimated deaths remain classified.

But, according to the New America Foundation which maintains a database of the strikes, the CIA and the military have carried out an estimated 416 drone strikes in Pakistan and Yemen, resulting in 3,364 estimated deaths, including militants and civilians. The Associated Press also has reported a drone strike in Somalia in 2012 that killed one.

The think tank compiles its numbers by combining reports in major news media that rely on local officials and eyewitness accounts.

Strikes in Pakistan spiked in 2010 under Obama to 122. But the number has dropped to 12 so far this year. Strikes were originally carried out with permission of the Pakistani government of Pervez Musharraf, though subsequent Pakistani governments have demanded strikes cease. Most of those killed by the strikes in Pakistan are militants, according to the New America Foundation database.

The CIA and the military have carried out some 69 strikes in Yemen, with the Yemeni government's permission.

The estimated timeline of strikes is:

2002 - Up to 10 killed in 1 strike in Yemen

2003 - None

2004 - Up to 7 killed 1 strike in Pakistan

2005 - Up to 15 killed 3 strikes in Pakistan

2006 - Up to 94 killed 2 strikes in Pakistan

2007 - Up to 63 killed 4 strikes in Pakistan

2008 - Up to 301 killed 37 strikes in Pakistan

2009 - Up to 634 killed in 56 strikes in Pakistan and Yemen

2010 - Up to 855 killed in 123 strikes in Pakistan and Yemen

2011 - Up to 647 killed 87 strikes in Pakistan and Yemen

2012 - Up to 621 killed in 81 strikes in Pakistan, Yemen and Somalia

2013 - Up to 118 killed in 22 strikes in Pakistan and Yemen

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