The President, Mrs McAleese, and the Taoiseach, Mr Ahern, have expressed their condolences to the family of the Irish soldier who died in Liberia last night.
Sgt Derek Mooney (33) from Blackrock, Co Dublin, died and Sgt Sean Baldwin (39) from Newbridge, Co Kildare, was seriously hurt in a crash yesterday.
The two Irish Rangers were travelling in a convoy when their jeep left the road around 40 miles from the Liberian capital of Monrovia.
Sgt Baldwin sustained serious leg injuries but is in a stable condition in hospital.
Mrs McAleese's office issued a statement this morning which said: "President McAleese has learned with great sadness of the death of Sgt Derek Mooney in Liberia.
The President has spoken with Lt Gen Mangan, Chief of Staff to convey her condolences to the Army and to the family of Sgt Mooney who died so tragically while serving his country abroad."
She also conveyed "her thoughts and prayers . . . and those of all the Irish people" to Sgt Sean Baldwin who was injured in the accident.
Mr Ahern also expressed his sympathy: "Our thoughts and prayers are with Sgt. Mooney's family and with his comrades in the Defence Forces serving in Liberia, at this sad and difficult time."
He said Irish efforts in the war-ravaged country "on behalf of the people of Liberia" will continue.