WASHINGTON (NewsNation) — The kidnapping of four American citizens in Mexico last Friday is sparking calls for drastic action by South Carolina Sen. Lindsey Graham (R).

As the FBI continues to search for the four Americans believed to have been kidnapped by a Mexican cartel in a case of mistaken identity, Graham said he would propose new legislation to take action against the cartels.

In a FOX News interview, Graham proposed the U.S. use military force against Mexican drug cartels that are terrorizing Americans and flooding our nation’s streets with deadly fentanyl.

The senator said he would follow former U.S. Attorney General William Barr’s assessment that the federal government should designate “the cartels as terrorist organizations.” Graham also said he would get tough on Mexico, not just for the kidnapping but for the overwhelming amount of illegal drugs crossing over the border.

The former AG said the U.S. needs to go a step further.

“Merely designating the cartels as terrorist groups will do nothing by itself,” Barr wrote. “The real question is whether we are willing to go after them as we would a terrorist group.”

Graham grilled incumbent Attorney General Merrick Garland on Capitol Hill last week on the issue. Garland said he was open to the possibility of labeling cartels as terrorists, but that designation typically comes from the State Department.

Rep. Dan Crenshaw (R-Texas) and Rep. Michael Waltz (R-Fla.) have already put forward a joint resolution calling for authorization for use of military force targeting Mexican cartels.

Graham said he would introduce new legislation that would officially designate cartels as foreign terrorist organizations under U.S. law to “set the stage to use military force if necessary to protect America from being poisoned by things coming out of Mexico.”

“I’d put Mexico on notice,” he said. “If you continue to give safe haven to fentanyl drug dealers, then you’re an enemy of the United States.”

Graham said he would tell the Mexican government that if it can’t clean up its act, the U.S. will have to do it.