British forces in southern Afghanistan have handed over responsibility for security in Sangin to US forces.
The British Government first announced the transfer of authority in July. Control of the area was handed from 40 Commando Royal Marines to the US Marine Corps.
Defence Secretary, Dr Liam Fox, said: "British forces have served in Sangin over the last four years and should be very proud of the achievements they have made in one of the most challenging areas of Afghanistan."
UK forces have been in Sangin since 2006. British troops will redeploy to central Helmand, where they will continue to lead the fight against the insurgency and assist in building a stable and secure Afghanistan, he said.
The number of British losses since the conflict in Afghanistan began in 2001 now stands at 337. Ministry of Defence spokesman Major General Gordon Messenger, a former commander of the UK Helmand Task Force, insisted the handover was not an admission of defeat.
He said: "We are seeing real and positive progress in areas that only a year or so ago were in a very different state."