The Texas National Guard has begun installing layers of razor wire in high-traffic areas for illegal crossings along the border with Mexico.

Gov. Greg Abbott on Monday tweeted images of the National Guard installing loops of the razor wire, writing “They’re working around the clock to secure the border in the federal government’s absence.”

Texas has boosted border security efforts under “Operation Lone Star,” which was launched in March to stop a surge of illegal crossings and flow of illegal drugs from Mexico. Abbott has called out the Biden administration and Congress for their failures to properly address the crisis.