Homeland Security Secretary Kirstjen Nielsen confirmed on Wednesday that military officials are looking into building their own barriers along the Southwest border.

Nielsen's comments come days after President Trump floated the possibility of using Pentagon funds to pay for his promised border wall, a move that was met with criticism from Democratic lawmakers and some veterans groups.

"What [Trump] meant is there are some lands that the Defense Department owns right on the border where we see illicit activity," Nielsen explained during a briefing with reporters at the White House.

"We're looking into options for the military to build wall or military installations on the border," she added.

The idea of working with military officials to construct a barrier along the U.S.-Mexico border comes as Trump plans to deploy National Guard troops to the border to assist immigration enforcement officials.

The administration is also working on a plan to close various loopholes that are regularly exploited by asylum-seekers and criminal illegal immigrants, Nielsen said Wednesday.