Mexico City, Mexico - Mexico's president warned the US on Thursday her country would never tolerate an "invasion" of its national sovereignty and vowed fresh legal action against American gunmakers after Washington designated cartels as terrorist organizations.

The remarks were the latest in a series hitting back at the administration of President Donald Trump, which has accused Mexico of not doing enough to stop undocumented immigration and drug smuggling.

Mexico is trying to avoid the sweeping 25% tariffs threatened by Trump by increasing cooperation in the fight against narcotics trafficked by the cartels in his sights.

The eight Latin American drug trafficking groups designated as terrorist organizations include Mexican gangs such as the Jalisco New Generation and Sinaloa cartels – two of the country's most powerful and violent criminal organizations.

Mexico Mexican drug lord seeks repatriation to avoid US death sentence

But the designation "cannot be an opportunity for the US to invade our sovereignty," President Claudia Sheinbaum told a news conference. "They can call them (the cartels) whatever they want, but with Mexico, it is collaboration and coordination, never subordination or interventionism, and even less invasion."

In an interview broadcast late Thursday on the social media platform X, US Secretary of State Marco Rubio attempted to allay those concerns.

"In the case of Mexico, the preference always is to work in conjunction with our partners in Mexico, and we can provide them a lot of information about who they are and where they're located," he said, referring to the newly designated criminal gangs.

Sheinbaum said Mexico would expand its legal action against US gun manufacturers, which her government accuses of negligence in the sale of weapons that end up in the hands of drug traffickers.

The lawsuit could lead to a new charge of alleged "complicity" with terrorist groups, she said.

Trump signed an executive order on his first day back in the White House last month saying that the cartels "constitute a national security threat beyond that posed by traditional organized crime."

Rubio said Thursday that the designations "provide law enforcement additional tools to stop these groups."

"Terrorist designations play a critical role in our fight against terrorism and are an effective way to curtail support for terrorist activities," he said in a statement.

Mexico Mexico defends US drone flights amid increased cross-border surveillance

While Rubio did not mention it, the move has raised speculation about possible military action against the cartels.

Tech billionaire Elon Musk, who has been given a prominent role in the Trump administration, suggested the designation "means they're eligible for drone strikes."

On Wednesday, Sheinbaum confirmed that the US had been operating drones spying on Mexican cartels as part of a collaboration that has existed for years.

According to The New York Times, Washington has stepped up secret drone flights over Mexico in search of fentanyl labs as part of Trump's campaign against drug cartels.

Sheinbaum said that she would present to Congress a constitutional reform to protect "the integrity, independence and sovereignty of the nation" including against the violation of its territory by land, air, or sea.

On Thursday, Canada – also under threat of 25% tariffs from Trump – joined the US in labeling seven drug cartels as "terrorist entities."

The groups sanctioned by Canada included the Gulf Cartel, the Sinaloa Cartel, the Michoacan Family, the United Cartels, MS-13, TdA, and the Jalisco New Generation Cartel.

Mexico says that between 200,000 and 750,000 weapons manufactured by US gunmakers are smuggled across the border from the US every year, often being used in crime.

The Latin American country tightly controls firearm sales, making them practically impossible to obtain legally.

Even so, drug-related violence has seen around 480,000 people killed in Mexico since the government deployed the army to combat trafficking in 2006, according to official figures.

While she has ruled out declaring "war" on drug cartels, Sheinbaum has quietly dropped her predecessor's "hugs not bullets" strategy, which prioritized tackling the root causes of criminal violence over security operations.

Her government has announced a series of major drug seizures and deployed more troops to the border with the US in return for Trump pausing tariffs for one month.

Mexican authorities also announced the arrest this week of two prominent members of the Sinaloa Cartel, including the head of security for one of its warring factions.