Photostream : Britain's Prime Minister David Cameron meets Commander of US and NATO forces in Afghanistan General David Petraeus

Britain's Prime Minister David Cameron , right, meets General David Petraeus, left, Commander of US and NATO forces in Afghanistan, inside 10 Downing Street, central London Thursday Oct.14, 2010. The talks in London have been overshadowed by revelations that a kidnapped British aid worker may have been killed by her American rescuers _ rather than her Taliban captors as first reported. .(Getty Images / AP Photo/ Daniel Deme, pool)

Britain's Prime Minister David Cameron (R) speaks to ISAF Commander General David Petraeus (L) at 10 Downing Street in Central London October 14, 2010. ( REUTERS/Pool/Daniel Deme )

General David Petraeus leaves 10 Downing Street after meeting with British Prime Minister David Cameron on October 14, 2010 in London, England. Petraeus, the top US commander in Afghanistan, has called for an investigation into the death of British aid worker Linda Norgrove, who was held hostage in Afghanistan. Ms Norgrove died after a failed rescue opperation by US forces on October 8, 2010 in Afghanistan. (Photo by Dan Kitwood/Getty Images)

U.S. General David Petraeus leaves Downing Street after his meeting with Britain's Prime Minister David Cameron in London October 14, 2010. ( REUTERS/Toby Melville )

General David Petraeus leaves 10 Downing Street in London Thursday, Oct. 14, 2010. British Prime Minister David Cameron raised the case of a slain British aid worker in a Downing Street meeting Thursday with NATO's top commander in Afghanistan, U.S. Gen. David Petraeus. Cameron earlier this week revealed that Linda Norgrove, a kidnapped British aid worker, may have been killed by her American rescuers _ rather than her Taliban captors as first reported. (AP Photo/Sang Tan)