Mexican President Claudia Sheinbaum on Tuesday made it clear that the Mexican government will not allow U.S. military strikes on its territory, even if the goal is to target cartel operations.
Her statement came one day after former President Donald Trump said he was willing to take any action needed to stop drug trafficking into the United States.
At the same time, diplomats from both nations were working to understand a recent event that may have involved an unintentional U.S. intrusion into Mexican land.
Confusing Signs Found on Mexican Beach Spark Controversy
On Monday, several men reportedly arrived by boat at a beach in northeastern Mexico and placed signs indicating that the area was restricted U.S. Department of Defense property.
Mexico’s Foreign Affairs Ministry confirmed that the country’s navy removed the signs later that day, as they appeared to be standing on Mexican soil.
The ministry also said it was unclear who installed the signs or why they were placed on national territory.
International Boundary Agency Steps In
President Sheinbaum explained that the International Boundary and Water Commission (IBWC) — the binational authority responsible for defining the U.S.-Mexico border — had begun investigating the matter.
The signs were found on Playa Bagdad, near where the Rio Grande flows into the Gulf of Mexico, causing alarm among locals.
Printed in both English and Spanish, the warnings declared the zone a “Restricted Area” controlled by the Department of Defense and prohibited unauthorized entry, photos, or sketches.
CBS 4 News Rio Grande Valley even circulated images of the signs online, fueling the dispute.
U.S. Pentagon Confirms Contractors Installed the Signs
On Tuesday, the U.S. Embassy in Mexico shared a Pentagon statement acknowledging that contractors were responsible for placing the signs marking “National Defense Area III.”
According to the Pentagon, recent changes in the Rio Grande’s depth and landscape may have altered the visible boundary between the two countries, creating confusion.
The statement also noted that Mexican authorities removed six signs based on their understanding of the border’s location.
The Pentagon assured that future work would involve better coordination to prevent similar misunderstandings.
Mexico Contacts U.S. Officials for Clarification
Mexico reached out to its consulate in Brownsville, Texas, and later to the U.S. Embassy in Mexico City. President Sheinbaum said it was eventually confirmed that the signs had been installed by contractors linked to a U.S. government agency.
She also pointed out that the Rio Grande frequently shifts its course, and that border treaties require clear reaffirmation of the international dividing line when such natural changes occur.
Area Near SpaceX Facility Adds Extra Sensitivity
The disputed zone sits close to the SpaceX Starbase in Boca Chica, Texas. This is the launch site used by SpaceX, which operates under contracts with the Department of Defense and NASA for future moon and Mars missions.
Earlier in June, Sheinbaum revealed that Mexico was investigating reports of metal and rocket debris from a SpaceX test explosion landing on Mexican territory.
Tensions are already heightened due to Trump’s earlier proposal to rename the Gulf of Mexico as the Gulf of America, an idea Mexico strongly opposed.
Sheinbaum Again Rejects U.S. Military Intervention in Mexico
While addressing reporters on Tuesday, Sheinbaum again stressed that Mexico will never permit foreign military involvement, even if framed as support against criminal groups.
She explained that Trump had previously suggested U.S. forces could intervene to fight cartels, but she repeatedly told him that Mexico handles its operations independently.
“We can cooperate and share information,” she said, “but no foreign government will operate inside our territory.”
Sheinbaum said she also communicated this stance to U.S. Secretary of State Marco Rubio, and both understood Mexico’s firm position.
Meanwhile, Trump reiterated Monday that he supports aggressive action, stating:
“Would I want strikes in Mexico to stop drugs? OK with me, whatever we have to do.”
The border incident involving misplaced U.S. defense signs has added fresh tension to U.S.-Mexico relations, especially as President Sheinbaum insists on defending Mexico’s sovereignty.
While both governments appear committed to cooperation, their interpretations of security responsibilities differ sharply.
As discussions continue, both nations will need to navigate boundary issues, cross-border security concerns, and political statements carefully to prevent further misunderstandings.
