He served as Chief of General Staff of the Armed Forces of the Republic of the Congo and was advisor to President Denis Sassou-Nguesso.

During the advent of democracy, Mokoko tried to depoliticize the armed forces in order to reduce the influence of the military in Congolese political life.

From October 15, 2014 to February 21, 2016 (date on which he was replaced by Professor Hacen El Lebatt, former Mauritanian Minister of Foreign Affairs).

[citation needed] On 13 February, Jean-Marie Michel Mokoko formalized his candidacy through a speech at the Brazzaville convention center in the presence of several leaders of the Congolese opposition.

[citation needed] A meeting was held the same day at the home of Aimé Emmanuel Yoka, Minister of Justice and maternal uncle of President Sassou-Nguesso, at the end of which the public prosecutor, André Oko Ngakala, made a statement on national television.

Addressing the question on his legal disputes, Mokoko stated "that he never wanted to escape the action of the justice of his country, while regretting this relentlessness against his person.

After Denis Sassou-Nguesso's contested victory in the 2016 presidential election, on 24 March Mokoko launched an appeal to the Congolese people, encouraging them to revolt[7] and to act in civil disobedience.

Accused of "undermining the internal security of the State", as well as "illegal possession of weapons and ammunition of war", he was placed under arrest warrant (detained in the Brazzaville remand center).

Étienne Arnaud, one of the three French lawyers of the accused, denounced a trial that was "exuberant and crudely political, with delusional decisions, wringing the neck of Congolese law".

[11] A two-page handwritten letter, written by Mokoko during his detention, was also made public by the French newspaper Le Monde, in which he says he "came up against the totalitarian machine”, which he considered to be helped by “foreign accomplices".

[13] In September 2019, the French Minister of Foreign Affairs, Jean-Yves Le Drian, raised the case of Mokoko and other opponents with President Denis Sassou Nguesso, declaring that he expected actions from him towards them.

[14] In October 2019, Jean-Marie Mokoko's lawyers asked the Minister of Justice to grant him an exit permit, so that he could attend the funeral of his mother, Louise Ongagna, who died at the age of 92, and of which he was the only child.

First presented by his relatives and his lawyers as having been contaminated by the Covid-19,[17] the latter denied this a few days later, specifying that he was in fact suffering from an attack of acute malaria and hypertension.

[17] On July 30, after solicitation from his lawyers, NGOs and political opponents, Denis Sassou-Nguesso authorized his medical evacuation to Turkey,[18] where he was admitted to the Ankara military hospital.