The return of British troops from Afghanistan could be accelerated if conditions on the ground improve, Prime Minister David Cameron has indicated.
In a key turning point for the conflict, President Barack Obama announced he was ordering home 10,000 American personnel by the end of this year, with another 23,000 to follow by summer 2012.
The move was swiftly matched by a French announcement of the phased withdrawal of their 4,000 military personnel in Afghanistan, with around 1,000 expected to be home by the end of next summer, while Germany said it aims to start pulling out its 4,900-strong force before the end of 2011. Downing Street said that an announcement on British troop levels would be made "in due course".
Mr Cameron has set a deadline of the start of 2015 for combat operations in Afghanistan to cease. He today made clear that the rate at which the UK's 9,500-strong force is reduced will depend on how their mission against the Taliban develops as well as progress in handing over security responsibility to Afghan authorities.
"We will keep UK force levels in Afghanistan under constant review," he said. "I have already said there will be no UK troops in combat roles in Afghanistan by 2015 and, where conditions on the ground allow, it is right that we bring troops home sooner."
Some 450 UK personnel are already due to be pulled out of Afghanistan by the summer, and speculation was rife in Westminster that the total returning home this year could reach 1,000.
Downing Street stressed that the UK's judgment on troop levels would be independent of the US announcement.
"We will take any decisions on troop numbers based on conditions as we see them on the ground," said Mr Cameron's official spokesman. "That will clearly have to reflect military advice and we will make an announcement when we are ready to do so."
Mr Cameron, who spoke to Mr Obama by telephone ahead of the announcement, said that the US president's 2009 "surge" of 30,000 troops had helped reverse the momentum of the Taliban insurgency and create the right conditions for the handover of security to Afghans from next month.
The head of the British armed forces, Chief of Defence Staff General Sir David Richards welcomed Mr Obama's announcement but added: "Our collective military efforts need to continue until Afghan security forces are able to assume responsibility for security across Afghanistan by the end of 2014."