The meeting comes less than a week after a British aid worker was killed during an operation to rescue her from kidnappers in Afghanistan.

Linda Norgrove may have been killed by a grenade thrown by American forces trying to free her.

"It's a long-standing meeting and has been in the diary for a number of weeks," the Downing Street press office said this week, adding that the discussion will center on the strategy in Afghanistan. Petraeus also will meet with UK Defense Secretary Liam Fox to talk about Afghanistan.

An investigation into Norgrove's death was to be launched this week and led by a senior officer from US Central Command, said an International Security Assistance Force official.

NATO and UK officials had said earlier she was killed by her captors, who detonated an explosive.

But Cameron said that statements made about Norgrove's death over the weekend were "highly likely to have been incorrect," although they were made "in good faith."

Cameron said he could not make a firm statement about the cause of her death until the investigation is complete. It will be a joint investigation between the US and UK.