He last visited the country five years ago as it sought to recover from a bloody and brutal civil war.

British troops moved in seven years ago to secure the airport at Lungi and played a major role in restoring stability to the west African state, alongside the United Nations.

Mr Blair also has personal memories of the country - his father Leo was once a visiting lecturer at Freetown University.

No details of the Prime Minister's programme were being released in advance.

But asked by reporters travelling with him whether his visit to Africa was about revisiting past triumphs - or failures - he replied: "When we go to Sierra Leone that is in part about what has happened in the past but it's about the future, too."

Mr Blair is keen to boost the fledgling democracy there and also build up the African Union so its peacekeeping force can help resolve similar crises in the future without outside intervention.

Mr Blair will fly on to Sierra Leone from Libya, where he had talks with veteran leader Colonel Mummar Gaddafi.

The two had a desert dinner on Tuesday night in the leader's tent and embraced warmly afterwards.

Mr Blair hailed a £455m deal for oil and gas exploration announced by BP to coincide with his visit as a sign of the "transformation" of the relationship between the UK and Libya.

Mr Blair also praised Libya for its help in counter-terrorism and the fight against al Qaida.