Serving with the Brigade Advisory Group, the soldier was working alongside an Afghan security forces patrol tasked with disrupting insurgent activity in the Mirmandab region of Nahr-e Saraj district, Helmand province, when he was caught in the blast from an improvised explosive device.
Spokesman for Task Force Helmand, Lieutenant Colonel Gordon Mackenzie, said:
"Sadly, I must report that a soldier from the 2nd Battalion The Mercian Regiment was killed in an explosion from an improvised explosive device while working alongside an Afghan security forces patrol to disrupt insurgents in the Nahr-e Saraj district of Helmand province.
"The thoughts and condolences of everyone serving in the Task Force are with his family and friends."
The soldier's family have been informed and have asked for a period of grace before further details are released.