"Secretary Esper has approved a request for assistance from the Department of Homeland Security and authorized the deployment of up to 4,000 DOD personnel to the southern border, beginning in October", the release said.
The troops will primarily be from National Guard units and will assist in monitoring the border as well as providing support with logistics and transportation of US Customs and Border Protection agents, the release also said.
The troops will not take part in law enforcement activities, the release added.
On 7 June, the United States and Mexico reached an agreement on curbing illegal migration through the US-Mexican border. Under the agreement, the United States vowed to refrain from imposing tariffs on Mexican goods, while the Latin American country committed to deploying its National Guard throughout the country and, especially, to its southern border to fight the influx of undocumented migrants.
Caravans of migrants from Central American countries seeking asylum began to move toward the United States through Mexico last fall. US President Donald Trump called the surge of arrivals a crisis and declared a national emergency in February to secure funds to build a wall on the border with Mexico.