MEXICO CITY — The US government shares responsibility for the latest outbreak of violence in the northwest Mexican state of Sinaloa, due to its anti-drug trafficking strategy, said Mexican President Andres Manuel Lopez Obrador on Thursday.

At his daily press conference, Lopez Obrador again demanded that the United States disclose the agreement it reached with one of the sons of former Sinaloa Cartel drug kingpin Joaquin "El Chapo" Guzman, which led to the arrest of Ismael "Mayo" Zambada, a leader of the cartel.

The incident unleashed a deadly wave of violence as drug traffickers loyal to "Mayo" and to "Los Chapitos," the sons of "El Chapo," began fighting each other in Sinaloa.

READ MORE: In Mexico, 19 bodies found in truck as violence spreads in southern state

"There was an arrangement and because of that arrangement -- which we still do not know what it consisted of or under what conditions the arrangement took place -- it led to confrontation for us in Sinaloa," Lopez Obrador told reporters at the National Palace in Mexico City.

Zambada, a longtime associate of "El Chapo," was arrested on July 25 in the United States.

READ MORE: US arrests Mexican drug lord 'El Mayo' and El Chapo's son in Texas

As of Tuesday, 30 civilians and two military personnel have been killed in the violence in Sinaloa, according to Mexican Defense Minister Luis Cresencio Sandoval.