MEXICO CITY — Former U.S. ambassador to Mexico Ken Salazar wrote in his upcoming memoir that former Mexican President Andrés Manuel López Obrador feared cartel co-founder Ismael 'El Mayo' Zambada would expose corrupt Mexican officials to U.S. prosecutors. Mexican President Claudia Sheinbaum rejected that account. BenBella Books is scheduled to release Salazar's memoir, titled "Borderlands: My Fight For an Inclusive America," next month.

Sheinbaum stated that López Obrador was concerned about U.S. meddling in Mexican affairs. "There was no worry about" what Zambada would tell U.S. prosecutors, she said. Salazar stated that he saw no proof linking López Obrador to cartel corruption. "I never saw any proof of it," he said. He also stated that an unidentified source, referred to as "the AMLO whisperer," provided the information about López Obrador's concerns.

Salazar added, "As far as I know, Andrés Manuel López Obrador was a president who strongly believed in Mexico and the sovereignty of Mexico." He also stated, "It was well known that Mexico's powerful transnational criminal cartels had compromised many government officials."

Mexican authorities arrested Ismael 'El Mayo' Zambada in July 2024 outside El Paso. Zambada subsequently pleaded guilty to smuggling-related charges and awaits sentencing in the United States. U.S. authorities stated that Joaquín Guzmán López, the son of Joaquín 'El Chapo' Guzmán, engineered Zambada's kidnapping and transport to the United States. Guzmán López surrendered to U.S. authorities when his plane landed near El Paso. He entered a guilty plea to federal drug charges in December 2025 and is awaiting sentencing. The Justice Department stated that Guzmán López received no cooperation credit for coordinating and committing the kidnapping of Zambada.

U.S. authorities denied involvement in Zambada's kidnapping in Mexico. Mexican authorities, however, suspect U.S. officials were behind the kidnapping and transport of Zambada to U.S. territory. Mexican, U.S., and Canadian officials are currently negotiating revisions to the North American free-trade agreement. Salazar resigned as U.S. ambassador following the election of Donald Trump. He also served as a U.S. senator and as U.S. secretary of the Interior under former President Obama.