Cameron hints at Afghan exit

David Cameron has said British troops could start withdrawing from Afghanistan as early as next year.

The Prime Minister, visiting the country on an unannounced trip, said: "In terms of next year, I think that it is possible. We have to deliver on the ground what's necessary. What I have seen today gives me cause of cautious optimism."

Mr Cameron also said the death of a paratrooper in an apparent friendly-fire incident in southern Afghanistan was "very tragic" but a consequence of "the fog of war".

"It is absolutely tragic when incidents like this happen and my heart goes out to the family concerned, to lose a loved one and to lose a loved on in this way is obviously a terrible thing. There will have to be a proper investigation," Cameron said.

Mr Cameron, who arrived on Monday, shrugged off US and Afghan criticism of the troops' performance, saying it no longer held true.

Troops deployed in the Taliban stronghold of Helmand were "not up" to the task of securing the province, American diplomats said in cables released by WikiLeaks last week.