NEW YORK — Former Mexican cartel kingpin Ismael “El Mayo” Zambada pleaded guilty Monday to U.S. drug trafficking charges, saying he was sorry for helping to flood the U.S. with cocaine, heroin and other illicit substances and for fueling deadly violence in Mexico.

“I recognize the great harm illegal drugs have done to the people in the United States and Mexico,” he said through a Spanish-language interpreter. “I apologize for all of it, and I take responsibility for my actions.”

Under the leadership of Zambada and Joaquín “El Chapo” Guzmán, prosecutors say the Sinaloa cartel evolved from a regional player into the largest drug trafficking organization in the world.

In pleading guilty, Zambada acknowledged the extent of the Sinaloa operation, including underlings who built relationships with cocaine producers in Colombia, oversaw the importation of cocaine to Mexico by boat and plane and the smuggling of the drug across the U.S.-Mexico border. He acknowledged that people working for him paid bribes to Mexican police and military commanders “so they could operate freely,” going all the way back to when the cartel was just starting out.

He traced his involvement in the illegal drug business to his teenage years, when he said he planted marijuana for the first time in 1969. He said he went on to sell heroin and other drugs, but especially cocaine and that from 1980 until last year, he and his cartel were responsible for transporting at least 1.5 million kilograms of cocaine, “most of which went to the United States.”

Zambada entered his plea in a Brooklyn federal court, two weeks after prosecutors said they wouldn’t seek the death penalty against him. Instead, he’s expecting to be sentenced Jan. 13 to life in prison.

The 77-year-old pleaded guilty to one count of racketeering conspiracy and one count of running a continuing criminal enterprise. He was arrested in Texas last year.

Prosecutors say Zambada presided over a violent, highly militarized cartel with a private security force armed with powerful weapons and a cadre of “sicarios,” or hitmen, that carried out assassinations, kidnappings and torture.

Lawyers for Zambada didn’t immediately respond to an email seeking comment Friday.

Guzmán was sentenced to life behind bars following his conviction in the same federal court in Brooklyn in 2019. His two sons, who ran a cartel faction, also face federal charges.

The Sinaloa cartel is Mexico’s oldest criminal group, with various incarnations dating to the 1970s. It is a drug trafficking power player: A former Mexican cabinet member was convicted of taking bribes to help the cartel.

Considered a good negotiator, Zambada was seen as the cartel’s strategist and dealmaker, thought to be more involved in its day-to-day doings than the more flamboyant Guzmán. Nevertheless, prosecutors have said Zambada also was enmeshed in the group’s violence, at one point ordering the murder of his own nephew.

In court Monday, he acknowledged the grave human toll of his drug trade, including lethal fighting between his armed guards and cartel rivals.

“These confrontations led to many deaths both of our enemies and of fighters on our side,” Zambada said. “Many innocent people were also killed.”

As he concluded his eight-minute remarks, he apologized “to everyone who has suffered from my actions.”

U.S. law enforcement sought Zambada for more than two decades, but he was never arrested in any country until he was taken into custody in Texas last year. He had arrived in a private plane with one of Guzmán’s sons, Joaquín Guzmán López. Guzmán López has pleaded not guilty to federal drug trafficking charges in Chicago; his brother, Ovidio Guzmán López, pleaded guilty last month.

Zambada has said he was kidnapped in Mexico and taken against his will to the U.S. He had often been at odds with Guzmán’s sons, dubbed the Chapitos, a term that translates to “little Chapos.”

Zambada’s arrest touched off deadly fighting in Mexico between rival Sinaloa cartel factions, apparently pitting his loyalists against backers of Guzmán’s sons.