In a sign of the increasing level of security cooperation between the two countries, an elite United States military unit known as the Asymmetric Warfare Group (AWG) is training Mexican soldiers in counternarcotics operations.

According to a Pentagon source cited by El Universal, the AWG held a joint training exercise in Colorado last April with elements of the Mexican Armed Forces.  Though the exact nature of the exercise is classified, the paper reports that the location was chosen in order to simulate the rugged terrain often favored by drug traffickers.

The U.S. army has trained with Mexican armed forces on several other occasions, but according to an anonymous Central Intelligence Agency (CIA) official, the AWG is especially suited for Mexico’s drug violence. “Asymmetrical war involves two groups with a significant difference in power whether it be in terms of weapons, tactics, or number, and that we observe in the case of the Mexican cartels and the Mexican Army; so this type of training is useful not just in military terms, but also in terms of intelligence to locate weaknesses and combat them, ” the official told El Universal.

This revelation comes days after a New York Times investigation said that the U.S. government is sending intelligence operatives and retired military personnel to Mexico to assist in counternarcotics operations in the country for the first time. As InSight Crime has noted, the security relationship between the U.S. and Mexico has reached a new level, due to the $1.4 billion dollar Merida Initiative. Still, seeing as the death toll in the country continues to rise, it is unclear whether the partnership has brought about significant improvements on the ground.