US troops at the US-Mexico border are laying down approximately 1,000 feet of razor wire fencing along the Texas side of the Rio Grande river underneath the McAllen-Hidalgo International Bridge, as three separate caravans of Central Americans make their way north in the hopes of claiming asylum.

Soldiers participating in "Operation Faithful Patriot" are working with US Customs and Border Patrol officers to install the fencing, according to the Department of Defense.

U.S. Army troops, part of “Operation Faithful Patriot” arrived to the U.S. border with Mexico, deployed by President Trump ahead of midterms. Soldiers spread out barbed wire along the Rio Grande in south Texas. #immigration #border #caravanamigrante #undocumented #army pic.twitter.com/PVD6YIbCvk — John Moore (@jbmoorephoto) November 2, 2018

During a Saturday campaign rally in Montana, President Trump said "Mexico is trying, they are trying but we’re different, we have our military on the border," adding "And I noticed all that beautiful barbed wire going up today. Barbed wire, used properly, can be a beautiful sight."

TRUMP: “Barbed wire used properly can be a beautiful sight." pic.twitter.com/BFuc3ljwfo — JM Rieger (@RiegerReport) November 3, 2018

A spokesman for the US Border Patrol told the New York Post that the fencing was part of "necessary preparations" for the caravans.

Troops lay barbed wire as caravan approaches pic.twitter.com/yFeiOO2pcd — Fox News (@FoxNews) November 4, 2018

WATCH: The U.S. military is installing a barbed wire fence near the Hidalgo–Reynosa International Bridge on the US-Mexico border. pic.twitter.com/bYvjPAgL6F — NBC News (@NBCNews) November 3, 2018

Troop arrivals

Around 900 troops have arrived at the US-Mexico border since the Trump administration announced the deployment on October 26.

The president vowed the forces would block the caravans, which contain thousands of migrants, from entering US turf. Military units are heading to outposts along the border from Texas to California. After saying about 5,000 active-duty troops would be deployed as part of Operation Faithful Patriot, Trump on Wednesday boosted the number from 10,000 to 15,000. A separate contingent of about 2,100 National Guard troops had already been deployed to work with Border Patrol in anticipation of the caravans, which have about 7,000 people total, according to the Defense Department. -NY Post

The original caravan continued on foot Saturday after Mexico rescinded an offer to bus them to Mexico City, citing a lack of water. They are currently making their way through the Gulf Coast state of Veracruz, and are around 750 miles from the US border. The caravan's numbers have dropped from 7,000 to around 4,000 over the last few weeks, while around 3,000 have applied for asylum in Mexico and others haver returned home.

On Friday night, Veracruz governor Miguel Ángel Yunes offered bus rides to the country's capital, however he quickly rescinded the offer, blaming maintenance work on Mexico City's water supply which he said left 7 million people without water over the weekend.

Mexican officials, meanwhile, have ceased to provide bus, truck and van rides to the group.

A second caravan of around 1,000 to 1,500 people from Guatemala, Honduras and El Salvador entered Mexico last week and is around 1,000 miles from the southern US border, while a much smaller caravan also entered Mexico from Guatemala on Friday - wading across the Suchiate River after Mexican authorities blocked access over a bridge.