LONDON - The head of Britain's armed forces is leaving his post six months early, the government announced Sunday, shuffling its top military team as it grapples with the unpopular conflict in Afghanistan.

Defence Secretary Liam Fox said the head of the armed forces, Air Chief Marshall Jock Stirrup, will leave his job in the fall. His term had not been due to end until April 2011. The top civilian defence official, Bill Jeffrey, will leave at the same time.

Fox told the Sunday Times newspaper the two men had been in their jobs "longer than they needed to be."

Stirrup was appointed in 2006 by the Labour government, which lost power in May to a Conservative-Liberal Democrat coalition.

Foreign Secretary William Hague said Sunday the two men were not being punished for the rising death toll in Afghanistan. He told the BBC they were leaving at "a natural time to have a change of personnel."

Britain has some 10,000 troops in Afghanistan; almost 300 have died there since the 2001 invasion. The most recent casualty was a soldier from 1st Battalion The Mercian Regiment, killed in an explosion in Helmand province on Saturday.

Some officers and defence officials have accused the previous Labour government of underfunding front-line troops.

Hague said some aspects of defence policy "hadn't been run as well as it might have been," but that responsibility lay with politicians, not civil servants.

Prime Minister David Cameron's new administration has said Britain is committed to Afghanistan but is also keen to offer war-weary Britons an exit strategy. Cameron and other officials hope to speed up the hand-over of control to Afghan security forces.

The government is also under pressure to cut defence spending as part of moves to slash Britain's record deficit.

Fox said there could be cuts to the size of the armed forces after a major defence review later this year. He said no area of the military, apart from the Trident nuclear program, would be off-limits.

"It may be the case that there are some functions we need less of and some we need more of, so it's very unlikely that any of the services will look exactly the same after the review," he told the BBC.