The Trump administration is allowing troops stationed at the U.S.-Mexico border to engage in some law enforcement activities and, if necessary, use lethal force.

Defense Secretary Jim Mattis confirmed to reporters on Wednesday that he had received a Cabinet order signed by White House Chief of Staff John Kelly, not President Donald Trump, making engagement guidelines less restrictive.

"The president did see a need to back up the Border Patrol [officers], and we received late last night an additional instruction authorizing us to implement additional measures. We're sizing up what those are. We already talked with folks over at DHS [Department of Homeland Security]," Mattis said.

He added that he wouldn’t take any action unless he heard from DHS.

"The secretary of homeland security has to ask me to do stuff. I now have the authority to do more. Now we'll see what she asks me for," Mattis said. (VOA)

• Members of the U.S. military install multiple tiers of concertina wire along the banks of the Rio Grande near the Juarez-Lincoln Bridge at the U.S.-Mexico border, Nov. 16, 2018, in Laredo, Texas.