U.S. Army troops with the 16th Military Police Brigade install razor wire atop the U.S.-Mexico border wall just east of the DeConcini Port of Entry in Nogales. More than 5,600 active-duty troops have been deployed along the border in Arizona, California and Texas.

About 1,500 troops have been deployed to Southern Arizona to help customs officers and border agents secure the border ahead of the expected arrival of large groups of migrants and asylum-seekers slowly making their way through Mexico.

Since arriving last weekend, soldiers have been building housing tents at Davis-Monthan Air Force Base, adding razor wire to the top of the fence near the downtown port of entry in Nogales, and surveying other parts of the border along with Border Patrol agents. Troops assigned to the border will also be housed at Fort Huachuca.

Photos released by the Department of Defense show soldiers and Border Patrol agents walking along the international line near Bisbee. There are also similar photos taken near Sasabe and Lukeville, where large groups of mostly Central American families and unaccompanied minors have been crossing into the state.

The soldiers are part of a group of more than 5,600 active-duty troops deployed to support Customs and Border Protection, of which 1,300 are in California, 2,800 in Texas, and the rest in Arizona. The Department of Defense anticipates more than 7,000 total will be sent to the southern border at the request of the Trump administration.

More details about the deployment and their duties along the border are expected to be provided Friday.