More than 100 U.S. soldiers will travel to Mexico this month to participate in joint training exercises with Mexican military personnel in the northern state of Chihuahua.

The federal Senate on Monday granted President Claudia Sheinbaum the authority to allow the entry into Mexico of 139 U.S. Army troops, who are scheduled to land at the Santa Gertrudis Air Force Base south of Chihuahua city this Sunday. 

The granting of that authority comes amid security-related tension in the Mexico-U.S. relationship.

Among the causes of that tension are the CIA’s alleged participation in a drug lab raid in Chihuahua in April without the knowledge or authorization of the Mexican government; U.S. prosecutors’ drug-trafficking accusations against Sinaloa Gov. Rubén Rocha Moya and other current and former officials; and suggestions from Trump administration officials that the U.S. could take unilateral action against Mexican drug cartels on Mexican soil.

While each of those developments has drawn the ire of Sheinbaum, the president remains committed to cooperating with the Trump administration on security on the proviso that Mexican sovereignty and territorial integrity are respected. One example of that cooperation is a joint anti-drone operation that is currently taking place on the border between Tijuana and San Diego.

U.S. soldiers have previously traveled to Mexico to undertake joint training exercises with Mexican personnel. However, the U.S. contingent set to arrive in Chihuahua on Sunday is larger than previous ones that have come to Mexico.

Where will the joint training exercises take place?

The joint training exercises will take place at the Centro Nacional de Adiestramiento (National Training Center), located in Santa Gertrudis in the municipality of Saucillo, Chihuahua. The CNA is the Mexican military’s largest training facility.

Among the simulated combat exercises U.S. and Mexican military personnel will conduct are the destruction of sniper positions; the seizure of an airfield; an air assault; the destruction of a fuel-supply point; and the capture and extraction of a target using live fire.

The U.S. soldiers will stay at the CNA during their time in Mexico.

What is the objective of the training exercises?

The Senate said in a statement that the aim of the joint training exercises is to “strengthen operational capabilities between the United States and Mexican Armed Forces through the planning and execution of military operations under the principles of respect, sovereignty and territorial integrity; shared responsibility; mutual trust; and collaboration without subordination.

The Senate said that the joint training “will not only have a positive impact on strengthening individual and collective preparedness, but will also contribute to the improvement of bilateral military cooperation mechanisms.”

How long will the US soldiers remain in Mexico?

The U.S. troops will arrive in Chihuahua on a U.S. Air Force plane on Sept. 20 and return to the United States on Sept. 30. Therefore, the soldiers will be in Mexico for a total of 11 days.

The Senate noted that the U.S. troops will enter Mexico “with weapons.”

Which division of the US army to the soldiers belong to?

The 139 soldiers coming to Mexico belong to the 101st Airborne Division of the U.S. Army. The division, known as the “Screaming Eagles,” is the only air assault division of the United States Army. It is based at Fort Campbell, Kentucky.

With reports from La Silla Rota, El Economista and El Financiero