Sen. Markwayne Mullin (R-OK) on Tuesday urged Americans planning spring break trips to Mexico to cancel their plans, warning that the country is experiencing violent unrest following the killing of cartel leader Nemesio Rubén Oseguera Cervantes, known as “El Mencho.”

Mullin made the remarks during an appearance on CNBC’s Squawk Box, recounting that his chiropractor had called him to say he still planned to visit Cancún. “Are you crazy?” Mullin said in response. “No one should be going down there right now. It is very volatile, and the United States is laser-focused on watching what’s taking place.”

The warning comes after Mexican troops conducted operations in Tapalpa, Jalisco, on Sunday, targeting El Mencho, a former police officer who became head of the Cartel de Jalisco Nueva Generación. U.S. authorities consider the cartel a major supplier of fentanyl into the United States. El Mencho had carried a $15 million U.S. bounty and rose to power following the arrest of Joaquín “El Chapo” Guzmán. The cartel has grown over the past 15 years into a global trafficking organization operating in 21 of Mexico’s 32 states.

Following El Mencho’s death, cartel members set cars on fire and blocked roads across several states, and violent clashes were reported in parts of western Mexico. Mexican authorities later said the situation had been “stabilized,” with transit corridors reopening and airline operations returning to normal, including Puerto Vallarta International Airport. The Mexican Embassy in the U.S. confirmed that some local security measures remain in place but emphasized ongoing coordination with international partners to maintain safety in tourist areas.

The U.S. State Department’s travel advisory for Mexico remains in effect. Earlier this month, the U.S. government issued a shelter-in-place order for Americans in Mexico, which has since been lifted.

Mullin also called the fragmentation of cartels following the operation “a great opportunity for us, and Mexico, to take them all out.” He added, “Now, are we going to eliminate all the drug trafficking in the world? Absolutely not. But can we get a handle on it again? Absolutely.”

The Cartel de Jalisco Nueva Generación is considered Mexico’s most powerful cartel. The Trump administration has designated it as a foreign terrorist organization.