British Defence Secretary Des Browne has warned that British troops could be engaged in Afghanistan for decades.
Asked when British soldiers would be withdrawn from Afghanistan, he told Sunday's The Peoplenewspaper: "We cannot risk it again becoming an ungoverned training haven for terrorists who threaten the UK."
He said: "It is a commitment which could last decades, although it will reduce over time."
"But there is only so much our forces can achieve. The job can only be completed by the international community working with the Afghan government and its army," he added.
Britain, which has about 7,800 troops operating in Afghanistan in a 40,000-strong NATO stabilisation force, is expected to increase that number over time as it draws down in Iraq.