Mexican President Claudia Sheinbaum has ordered an investigation into the role played by two US officials in a counter-narcotics operation in the northern state of Chihuahua.
The two died alongside two Mexican officials when their car crashed on their way back from an operation to destroy illegal drug labs, Chihuahua officials said.
Sheinbaum stated that neither she nor senior members of the federal security team had been informed about any joint US-Mexican operations.
The Mexican leader has been adamant that foreign officials can only operate on Mexican soil if given prior clearance at the federal level.
Sheinbaum has faced pressure from US counterpart Donald Trump to do more to stem the flow of drugs into the United States, but maintains that Mexico's sovereignty cannot be breached.
On Monday, Sheinbaum remarked, We did not have knowledge of any direct work between Chihuahua state and personnel from the US embassy.
She further emphasized the need to understand the circumstances of the operation to assess potential legal implications.
According to Chihuahua state officials, the two US nationals and two members of the Chihuahua State Investigation Agency (AEI) died on Sunday morning when their vehicle skidded off the road and plunged into a ravine, leading to an explosion.
US ambassador in Mexico, Ronald Johnson, identified the two deceased Americans as US embassy personnel.
Chihuahua State Attorney-General César Jáuregui described the two as instructor officers from the US embassy involved in common exchange training activities with Mexican authorities.
Jáuregui indicated that the crash occurred as they were returning from an operation that targeted clandestine synthetic drug labs.
When asked about the US officials' involvement, he clarified that they were engaged in basic training about eight or nine hours away from the operation site.
Sheinbaum stated officials from her government had sought information from both the US embassy and Chihuahua state authorities to determine if the operation breached Mexican national security laws, which prohibit joint operations without federal approval.
She reiterated that while her government collaborates with the US on intelligence sharing, there are no joint operations on land or in the air.
