FIRST ON FOX: The Trump administration is seeking to disrupt with a sweeping set of sanctions a sprawling Sinaloa cartel network accused of corrupting Mexican officials just across the U.S. border.

Los Mayos, a powerful faction of the Sinaloa cartel, and its U.S.-born leader are accused of funneling fentanyl and drug money through California and hiring hitmen to kill rivals on American soil.

The Treasury Department, according to material exclusively obtained by Fox News Digital ahead of their public release on Tuesday, will sanction 21 individuals and 25 entities in a crackdown against Los Mayos and their alleged illegal activity within U.S. borders.

The targets of the sanctions include Ismael Zambada Sicairos, known as "Mayito Flaco," a dual U.S.-Mexican citizen born in Anaheim, California, whom Treasury describes as the "undisputed head" of Los Mayos. MEXICAN GOVERNOR FACING US DRUG CHARGES SEEKS LEAVE JUST ONE DAY AFTER RETURNING TO OFFICE The action lays out how one of Mexico’s most powerful cartel factions allegedly maintains its grip on two critical trafficking corridors along the U.S. border — through political and police corruption, money laundering and violence that Treasury says has extended into Southern California.

It also exposes what Treasury describes as deep cartel penetration of government and law enforcement in Baja California, the Mexican state bordering California.

The Treasury says Sinaloa-linked "narco-corruption has reached the highest levels" of the state government, alleging that the ex-husband of Gov. Marina del Pilar Ávila Olmeda used his political influence to protect cartel operations and that a former Mexicali public security chief accepted bribes to allow the cartel to exert control over municipal police.

The allegations shed new light on a controversy that erupted last year when the U.S. revoked the visas of both Ávila and her then-husband, Carlos Torres Torres.

The State Department revoked Torres’ U.S. visa in May 2025 over what Treasury now describes as his "cartel affiliation and work on behalf of the Sinaloa cartel." Olmeda’s U.S. visa was also revoked around the same time, though U.S. officials did not publicly disclose a reason for the action against her.

The Department of War also played a role in the effort through Joint Interagency Task Force-Counter Cartel, which works with federal law enforcement, intelligence agencies and Treasury to identify cartel financial and facilitation networks.

"These sanctions reflect the impact of sustained interagency collaboration and intelligence fusion in identifying and disrupting the networks that enable violent transnational cartels," Brig. Gen. Maurizio Calabrese, director of JIATF-Counter Cartel, told Fox News Digital.

Calabrese said the task force contributed analysis and operational insight on cartel-linked financial and facilitation networks to support the broader effort behind the sanctions.

POTENTIAL SECURITY THREAT PROMPTS US TRAVEL SUSPENSION FOR BORDER CITY ON ALERT Treasury also alleges the cartel’s reach extended directly into California.

Lorenzo Castillo Maldonado, an associate in Mayito Flaco’s network, allegedly hired hitmen on the cartel leader’s orders to kill rival cartel members in Southern California. Another part of the network allegedly worked with complicit Southern California money exchanges to collect bulk cash from U.S. drug sales and move the proceeds back to Mexico.

The sanctions are aimed in part at disrupting Los Mayos’ grip on the Tijuana and Mexicali "plazas," strategic corridors Treasury says the cartel uses to move fentanyl and other narcotics into the U.S.

"Today’s action underscores that no cartel kingpin, corrupt Mexican government official, or financial facilitator is beyond the reach of Treasury’s authorities," Treasury Secretary Scott Bessent said. "Our message is clear: the Trump administration will identify and disrupt any cartel actor who threatens our security or the integrity of our financial system." The designations effectively cut the targets off from the U.S. financial system, blocking property and assets under U.S. jurisdiction and generally barring Americans from doing business with them. Foreign financial institutions that knowingly facilitate significant transactions for sanctioned individuals could also face U.S. sanctions.

At the center of Tuesday’s action is Mayito Flaco, who Treasury says has emerged as the undisputed leader of Los Mayos following the July 2024 arrest of his father, longtime Sinaloa cartel kingpin Ismael "El Mayo" Zambada Garcia.

SINALOA CARTEL BOSS 'EL MAYO' SENTENCED TO LIFE, ORDERED TO PAY $15B IN DRUG TRAFFICKING PROFITS El Mayo’s arrest set off a violent struggle between Los Mayos and Los Chapitos, the Sinaloa faction led by sons of Joaquin "El Chapo" Guzman. Treasury says the two factions remain locked in a costly internal war that has forced both sides to rebuild their leadership and alliances.

Mayito Flaco, 44, was born in Anaheim in 1982 and later filed a U.S. name change to Fernando Sicairos Aispuro, according to Treasury. He was federally indicted in California in 2014 on drug trafficking and money laundering charges and remains a fugitive in Mexico.

The Treasury says he now commands Los Mayos’ drug trafficking, murder, extortion, corruption and kidnapping operations.

The sanctions also target Torres’ brother, Luis Alfonso Torres Torres, whom Treasury accuses of collecting bribes and laundering illicit funds through companies and political campaigns.

Former Mexicali Public Security Director Pedro Ariel Mendivil Garcia is also being sanctioned. The Treasury alleges Mendivil accepted bribes from Los Rusos leader Juan Jose Ponce Felix, known as "El Ruso," in exchange for allowing the cartel to exert control over municipal police, facilitate drug trafficking and carry out enforcement operations.