New Delhi, April 8 -- A California man who co-founded one of Mexico's most powerful and violent drug cartels pleaded guilty on Tuesday in the U.S. to a federal narcotics conspiracy charge.

Erick Valencia Salazar formed the Jalisco New Generation Cartel with Nemesio Oseguera Cervantes, the drug lord known as "El Mencho" who was killed by the Mexican army in February.

Valencia Salazar, 49, of Santa Clara, California, faces a mandatory-minimum prison sentence of 10 years and a maximum of life in prison after pleading guilty in Washington, D.C., to one count of conspiring to distribute cocaine for U.S. importation. Chief Judge James Boasberg is scheduled to sentence him on July 31.

Valencia Salazar was a member of the Milenio Cartel before...