MEXICO CITY, April 27 (Reuters) - Mexican President Claudia Sheinbaum said on Monday that her government told the United States, in a ‌diplomatic note, that the unauthorized presence of U.S. officials at ‌an anti-narcotics operation in the northern state of Chihuahua should not be repeated.

The incident came ​to light after two U.S. officials, along with two Mexican officials, were killed in a car crash on April 19 after the operation. Sheinbaum has said the federal government was not aware of the participation of the U.S. ‌officials, who sources told ⁠Reuters were CIA officers.

"What we told (the U.S.) was that the federal government didn't know about the involvement of these ⁠people (in the operation) and we hope that it's an exception," Sheinbaum said in her daily morning press conference.

Mexico requested that "from now on, as has been done, ​our constitution ​and national security law should be ​followed," Sheinbaum added, saying that ‌the U.S. had indicated its agreement.

On Saturday, Mexico's security cabinet said in a statement that the U.S. officials lacked formal accreditation to participate in security activities in Mexico and that one of them had entered the country as a tourist.

The deaths of the two Americans rekindled U.S.-Mexico tensions ‌over security cooperation. The presence of U.S. ​personnel in anti-cartel operations is a deeply sensitive ​matter in Mexico. Sheinbaum ​has long maintained that she welcomes intelligence sharing and security ‌cooperation but will not accept U.S. ​agents or forces ​participating in operations on Mexican territory.

In contrast, U.S. President Donald Trump has repeatedly called for greater use of U.S. military force to ​combat Mexican cartels, and ‌has threatened that the U.S. could go it alone if Washington ​feels Mexico isn't doing enough.

(Reporting by Raul Cortes; writing by ​Kylie Madry; editing by Stephen Eisenhammer)