Members of the congressional Border Security Caucus toured the Texas-Mexico border Friday in an effort to gain insight into the ongoing surge of border crossings.

Congressman Lamar Smith (R-Texas) formed the Border Security Caucus in 2014 and opened it to any member of Congress who believes the border needed increased enforcement. Friday's tour was the first time members of the caucus traveled together to the Rio Grande Valley.

"One of the figures that we heard today was that only a fraction of those who are coming across the border illegally are actually being apprehended," Smith said.

While members of the caucus praised law enforcement's dedication, they said the Obama Administration wasn't providing enough technology or personnel.

"We don't know who's coming over the border when these kinds of things happen and it's a national security issue," said Rep. Diane Black (R-Tennessee).

Earlier this week, Department of Homeland Security Secretary Jeh Johnson announced that border apprehensions in January dropped by 36 percent from the previous month.

Smith, however, argued that the dip is likely to be temporary and that immigration policies must be enforced to ensure a permanent decrease.

"They are asked 'what drove you to come up this far north? What made you want to come into this country illegally?' Seventy percent say 'it's the policies of the administration, it's their immigration policies, we know we will be given asylum; we know we will be able to stay.' That's why they're coming, not because of violence back home," Smith said.

Five members of the Border Security Caucus took part in the tour. The caucus consists of more than 100 members of Congress.