Areas now under the security control of international forces will be handed over to the Afghan government as part of the West's exit strategy.
They include Nad-e-Ali and Marjah, two districts in Helmand which had been the scene of fierce fighting in the past. The provincial capital, Lashkar Gar, was transferred to the Afghan government last July.
Separately, the Ministry of Defence confirmed yesterday that a soldier from 5th Battalion The Rifles has been killed in the Babaji area of the Nahr-e Saraj district. The death takes the number of British troops who have died in Afghan to 390.