Sergeant Luke Taylor, who was 33 and of the Royal Marines, and 25-year-old Lance Corporal Michael Foley, of the Adjutant General's Corps (Staff and Personnel Support), were shot and killed by an Afghan soldier at the main entrance to Lashkar Gah Main Operating Base in Helmand province on Monday.
Sgt Taylor, from Bournemouth, Dorset, leaves behind his wife Nicola and their son Roan, while L/Cpl Foley, from Burnley, Lancashire, leaves his wife Sophie and their three sons Calum, Warren and Jake.
Asked whether the operation in Afghanistan was working, Hammond said it was and that, although tragic, the incident was 'rare'.
Today the soldier's friends, family and colleagues paid tribute to the two servicemen.
The shooting of Sergeant Luke Taylor and Lance Corporal Michael Foley was the latest in a string of "green on blue" attacks in which members of the Afghan security forces have opened fire on international allies.
An Afghan soldier killed the British men at the main entrance to the base in Helmand's capital before being shot dead himself.