Law enforcement officers working along the U.S.-Mexico border are stepping up efforts to respond to what is in effect a war going on south of the border, where drug cartel violence has spun out of control.

In Texas, where the two countries are separated only by the Rio Grande River, stopping the violence from spilling into the United States means taking to the water -- with 34-foot-long gunboats that pack some serious firepower.

The stakes are high. Since 2007, roughly 56,000 people in Mexico have been killed in the escalating drug cartel violence. The U.S. government and local police agencies are working around the clock, 365 days a year to try and stop the flow of drugs, weapons and illegal immigrants into America from our southern neighbor.

Of the nearly 2,000-mile border with Mexico, about 1,200 of it is in Texas. The terrain here is very different compared to California, New Mexico and Arizona -- states with dry land on the border.

The narrow and winding Rio Grande, meanwhile, is a hotbed of activity, since you can literally swim from one side to the other in just a few minutes. Officials say this makes it extremely enticing for smugglers, which is why authorities have to be one step ahead.

It’s why the Texas Department of Public Safety has rolled out the big guns: Four new “shallow water interceptors” are now patrolling the river, and two others will be commissioned soon. Those will be responsible for guarding the intercoastal waterway, where cops are seeing a spike in smuggling activity through the Gulf of Mexico.

These gunboats are outfitted with bullet-proof panels, fully automatic machine guns and 900-horsepower engines. Their ability to cruise through the water at fast speeds is designed to not only serve as an intimidating force on the water, but also to fight back.

“If we get into an ambush situation, our No. 1 priority is to get out of harm’s way,” said Lt. Charlie Goble of the Texas Highway Patrol’s Tactical Marine Unit. “It’s very important for us to be better armed than they are.”

The vessels cost about $558,000 a piece and were paid for with money set aside by the Texas Legislature and Department of Homeland Security grants. They’re just one more tool in the law enforcement toolbox of helicopters, ground units and weapons being used to wage the war against these powerful cartels, which will stop at nothing to get their cargo into this country.

“Machine guns on the ground are one thing,” Maj. Bob Bailey of the Texas Highway Patrol’s Special Ops Division told Fox News. “This is just another asset to be in those remote areas where the cartels exploit our border, our river, our citizens.”