WATCH: Ted Cruz SLAMS Kamala and Biden over worsening border crisis

"Three decisions drove this crisis, immediately halting construction of the border wall. That happened on day one. Reinstituting the failed policy of catch and release. That also happened on day one, and most indefensibly, ending the incredibly successful remain in Mexico international agreement," Senator Cruz said.

"Remain in Mexico last year produced the lowest rate of illegal immigration in 45 years. This year, because Joe Biden and Kamala Harris refused to enforce the law, It continued to be utterly lawless. We are seeing the highest rate of illegal immigration in 21 years," Cruz continued.

Previously, the White House claimed Vice-President Harris was handling the "root causes" of the border crisis. This claim was made in September when thousands of Haitians crossed into the US at Del Rio, Texas.

"This is a human catastrophe and disaster. Texas is paying the price. The last couple of weeks, I did roundtables with farmers and ranchers in South Texas, who described the chaos of finding dead bodies on their ranch land, day after day after day, who described moms in South Texas, who described that they wouldn't let their teenage children go outside unless they carried a loaded firearm. Because there's so many human traffickers and narcotics traffickers crossing across their properties."

"This is a humanitarian crisis. It's a public health crisis. It's a national security crisis. And right now, Joe Biden and Kamala Harris refuse to do a damn thing about it. Joe Biden won't even go to the southern border and Kamala Harris refuses to go to the Rio Grande Valley, the epicentre of this tragedy. This tragedy needs to end, and Joe Biden and Kamala Harris need to follow the law," Cruz concluded.