Mining is the biggest brief in his portfolio because minerals, particularly diamonds, have been the key natural resources behind Botswana's remarkable economic growth since it achieved independence in 1966.

However, a threat to the economy is looming as Tibone, 57, sees a levelling off in diamond production in the coming years.

At present, diamonds account for one-third of Botswana's gross domestic product, about 50% of total government revenues and 80% of exports.

Water