Britain will halve its number of troops in Afghanistan by the end of 2013, Prime Minister David Cameron said, handing over security to Afghan forces more than a decade after the US-led invasion.
By the end of 2013, Britain will maintain about 5,200 troops in Afghanistan from around 9,000 now, he told parliament, according to the Wall Street Journal.
"Because of the success of our forces and the Afghan National Security Forces... by the end of 2013 we will be able to see troops come home."
The NATO mission finishes in Afghanistan in late 2014 — with the US expected to make sizeable cuts in its 66,000-strong force.
Last month, France — which has lost 88 troops in Afghanistan — ended combat operations there and pulled hundreds of troops out of a volatile region northeast of Kabul, having vowed to end its combat role faster than its NATO allies.
The UK has the second biggest foreign force in Afghanistan after the US, its long, costly involvement has taken the lives of 438 British troops.
According to the Associated Press, the announcement came after a lengthy phone discussion between Cameron and President Barack Obama.
The withdrawal of British troops from Afghanistan will start next April, according to Defense Secretary Philip Hammond.
Hammond said fewer replacements would be sent over in the spring when the six-monthly rotation of British forces goes ahead as scheduled. A further reduction would come after the summer fighting season in September or October, Hammond said.
However, Britain will join the US in leaving behind an undisclosed number of soldiers after 2014 to continue the fight against any Taliban and Al Qaeda resurgence, Reuters wrote.
The WSJ cited senior officials in Washington as saying that the US was shifting focus away from fighting the Taliban to enabling Afghan forces.
Britain's Defense Secretary Philip Hammond, meantime, said his country's withdrawal was based on UK military advice and according to North Atlantic Treaty Organization strategy and planning by its International Security assistance Force.
The Afghan National Security Forces (ANSF) were already leading security in heavily populated parts of Afghanistan, he said.
"They set their own priorities, lead their own planning and conduct and sustain their own operations. By the middle of next year — marking a moment of huge significance for the Afghan people — we expect the ANSF to have lead security responsibility for the whole country."
Cameron, meantime, said Britain would also contribute about $114,000 a year to help pay for the ANSF, along with other aid.
"Because of the success of our forces and the Afghan National Security Forces ... we'll be able to see troops come home in two relatively even steps - 2013 and 2014," Prime Minister David Cameron told parliament.
Diplomatically speaking, he said, what Britain was "most focused on is bringing Afghanistan and Pakistan together."