Hundreds of Mexican soldiers were mobilized on Tuesday to the border with the United States as part of an agreement that halted U.S. tariffs on Mexican imports under the condition the Latin American country cracks down on fentanyl trafficking.

A line of Mexican National Guard and Army trucks rumbled along the border separating Ciudad Juárez and El Paso, Texas, on Wednesday, among the first of 10,000 troops Mexico has sent to its northern frontier following tariff threats by President Donald Trump.