Mezue ahịrịokwu na-esonụ: Na Congo-Brazzaville, Mondjo jere ozi dị ka onye isi ndị agha, ọ bụkwa onye nduzi nke nkuzi na ọmụmụ ihe na Marien Ngouabi Military Academy na Brazzaville site na 1987 ruo 1993. Ọ kwadoro onye ndu ndị nnupụisi bụ Denis Sassou Nguesso n'oge agha
June-October 1997 agha obodo; agha ahụ biri na Sassou Nguesso weghachite ike ma chụpụ President Pascal Lissouba. N'ọnwa Disemba 1997, a họpụtara Mondjo ka ọ bụrụ onye isi nke mpaghara ndị agha 1, nke gụnyere isi obodo akụ na ụba nke mba ahụ, Pointe-Noire; ọ nọgidere na post ahụ ruo afọ ise. A họpụtara ya ka ọ bụrụ onye isi ndị ọrụ nke ndị agha Congo na 20 Disemba 2002, e buliri ya n'ọkwa nke onye isi ndị agha ("général de division").