U.S. officials met with agents of the Mexican attorney general's office this week to discuss the recent escape from prison of drug kingpin Joaquín "El Chapo" Guzmán and coordinate efforts to recapture him, a Mexican government official said on Wednesday.
Representatives from the U.S. Federal Bureau of Investigation and the Drug Enforcement Administration met Mexican law enforcement officials in Mexico City on Monday to share information, the government official said, speaking on condition of anonymity.
Mexico has long sought to maintain its independence from the United States on matters of national security, but has taken fire from critics for not having previously extradited Guzmán to the United States.
U.S. prosecutors had said they would seek his extradition, and U.S. media reports earlier this year citing unnamed sources suggested that the U.S. government had made a formal request for Guzmán's extradition.
But no announcement of a formal request was ever made public and the Mexican attorney general's office said it had no plans to hand him over because he would serve his time in Mexico.
Other sensitive issues have also bubbled beneath the surface.
Mexico's Interior Minister Miguel Ángel Osorio Chong this week denied media reports that Mexico had been tipped off by U.S. authorities ahead of time that Guzmán was planning an escape.
The two neighboring countries would be "cooperating permanently" to try and catch Guzman again, and were discussing everything relevant to the operation, the Mexican official said.
The kingpin's escape on Saturday night from a maximum security prison through a tunnel leading right into his cell was a bitter blow to President Enrique Peña Nieto's anti-crime efforts.
Mexican security chiefs were aghast at the breakout and the government has said it could only have taken place with the help of prison guards and officials.
The government fired the director of the Altiplano prison, which had never suffered an escape.
Guzmán, Mexico's most high-profile criminal, was boss of the powerful Sinaloa cartel prior to his capture in February 2014. The cartel has smuggled billions of dollars worth of drugs into the United States and has been blamed for thousands of deaths.
Guzmán previously broke out of prison in 2001.