A man accused of being one of the leaders of a powerful Mexican drug cartel pleaded not guilty Tuesday to charges that he conspired to import and sell large amounts of cocaine and heroin in the United States.

Jesus Vincente Zambada-Niebla, 34, listened silently to an interpreter as his New York-based defense attorney, Edward Panzer, entered the plea before Judge Ruben Castillo.

An especially large security contingent were on hand for the hearing in what prosecutors are calling the largest international drug conspiracy case in the Chicago's history.

Authorities say Zambada-Niebla was an influential, second-generation member of the Sinaloa drug cartel, and that he helped move large amounts of cocaine and heroin from South and Central America to the United States from 2005 to 2008. They say hundreds of kilograms of cocaine were taken to Chicago.

Zambada-Niebla was arrested last year in Mexico City and was turned over to U.S. authorities on Thursday in what Justice Department officials said was a major step forward in the war on drugs. The Drug Enforcement Administration led the Chicago-based portion of the investigation, but numerous other federal and local law enforcement officials also took part.

"There is quite a bit of evidence in this case," Assistant U.S. Attorney Thomas Shakeshaft told Castillo.

The extraordinary security in and around the courtroom reflected the concern of federal officials about the potential for violence by the cartel, which is named for the Mexican state of Sinaloa.

Zambada-Niebla is charged with conspiracy to possess and distribute more than five kilograms of cocaine and more than one kilogram of heroin. He is also charged with conspiracy to import more than five kilograms of cocaine and more than one kilogram of heroin into the United States.

The maximum penalty on both counts is life.

Federal prosecutors say cartel members discussed striking back against the war on drugs by acquiring weapons and using them to attack unspecified Mexican and American installations. The indictment provides no details of the discussions.

Zambada-Niebla was among three dozen defendants indicted in August in Chicago and is also charged in a separate case pending in the nation's capital.

U.S. Attorney Patrick J. Fitzgerald said last week that the extradition of Zambada-Niebla was "an extremely significant development in the United States effort to prosecute international drug importation conspiracies wherever the defendants may be operating."

Panzer and another New York-based defense attorney, George L. Santangelo, left the courthouse declining to comment on the case. They told Castillo that they would be bringing in a Chicago-based attorney to work with them.

Also charged in the indictment are the two alleged top leaders of the Sinaloa cartel, Joaquin "el Chapo" Guzman-Loera and Ismael "el Mayo" Zambada-Garcia. Federal officials said Zambada-Garcia is the father of Zambada-Niebla.

Both of those men are currently at large.