The former Mexican defense minister Salvador Cienfuegos is expected to plead not guilty to drug trafficking charges in New York on Thursday, in a case that has deeply strained U.S. and Mexican anti-cartel cooperation.

Cienfuegos, until two years ago a top player in Mexico’s war on drug gangs, was arrested at Los Angeles International Airport last month in a U.S. Drug Enforcement Administration (DEA) operation.

He is due to appear in Brooklyn federal court later on Thursday.

Edward Sapone, a lawyer for Cienfuegos, in a statement said

his client is presumed innocent of the charges in the four-count indictment.

“My legal team and I will ensure that Gen. Cienfuegos’ constitutional rights are protected as we zealously defend him,” said Sapone, whose website mentions his previous defense work for the Mexican government and for an “advisor to a Mexican president.”

Cienfuegos served as defense minister for six years under former President Enrique Pena Nieto. The arrest shocked the Mexican military establishment and put pressure on U.S. diplomatic ties, particularly in relation to security cooperation that had become increasingly close over the past 30 years.

“Regardless of whether Cienfuegos is guilty or not, all of this is now being questioned by the armed forces in Mexico; they’re very angry,” said Arturo Sarukhan, a former Mexican ambassador in Washington.

In a sign of the growing tensions, Mexican President Andres Manuel Lopez Obrador has criticized the lack of information shared prior to the arrest and warned of a review of cooperation agreements.

He has also questioned the role of the DEA and other U.S. agencies in Mexico, saying they worked closely for years with officials later accused of collaborating with criminals.

The president said he will shortly announce a review of the terms of cooperation with U.S. agencies in Mexico, as well as how such arrest warrants are issued.

Reuters