US troops appear to have arrived on Mexico’s northeast coast this week, installing signs declaring the area “no-go” by the Pentagon, as US President Donald Trump promises to crack down on illegal drug trafficking from Latin America.
President Trump and Mexico’s Claudia Sheinbaum are locked in a war of words over the threat of a U.S. attack on an alleged Mexican drug cartel.
Now let’s take a closer look at what happened and what it means.
what happened?
On Monday, unidentified men arrived at a beach in northeastern Mexico by boat and planted signs in the sand that read “Warning: Exclusion Area” in English and Spanish.
Neither side has confirmed the exact location of the beach, but a video circulating on social media and local news purports to show Mexican marines removing the sign. The video is said to be from a beach frequented by locals and fishermen known as Playa Baghdad, in the area where the Rio Grande flows from south-central Colorado to the Gulf of Mexico. Al Jazeera has not been able to verify the video.
🚨 Playa Baghdad Incident, Matamoros
Pescadores condemns EE.UU’s personal military actions. Showing 6 articles for “Area Restringida del Departmentamento de Defensa”.
La Marina Mexicana Los Retiro de Mediato and Restotablecio El… pic.twitter.com/v8ai7eKNCO— Aztec (@MORRIS80766176) November 18, 2025
The sign stated that the area was Department of Defense property and had been declared off-limits by the “commander in command.” It also states that “unauthorized entry is prohibited” and that “anyone found here may be detained and searched.” Photography and drawing were also prohibited.
The Gulf of Mexico borders Cuba. States in eastern Mexico, including Tamaulipas, Veracruz, Tabasco, Campeche, Yucatan, and Quintana Roo. and the U.S. Gulf Coast states: Texas, Louisiana, Mississippi, Alabama, and Florida.
President Trump signed an executive order in January renaming the Gulf of Mexico the Gulf of America, but Mexico rejected the order. This change is now reflected in Google Maps for users in the United States.
How did Mexico react?
Late Monday, the Foreign Ministry announced that the Navy had removed the sign because it was on Mexican territory.
Sheinbaum said Tuesday that the International Boundary and Water Commission (IBWC) would be involved in resolving the dispute. “Rivers change course, flow slows down. According to the treaty, borders must be clearly demarcated,” she said at a daily news conference.
What is IBWC?
Founded in 1889, the IBWC is a bilateral agency that oversees border and water treaties between the United States and Mexico.
The organization consists of a U.S. division operating under the foreign policy guidance of the State Department and a Mexican division under the supervision of the Department of Foreign Affairs.
The organization is responsible for sharing and regulating water from the Rio Grande and Colorado rivers. Construction and operation of dams and reservoirs. Flood control; addressing border sanitation and water quality issues; and to maintain and mark international boundaries.
In the past, the IBWC has resolved border disputes between the United States and Mexico by overseeing border delimitation treaties.
In 1963, the 100-year-old Chamizal dispute over 600 acres (243 ha) of land near El Paso and Ciudad Juárez in the United States was resolved by the Treaty of Chamizal. It was agreed that the disputed land would be returned to Mexico and that the Rio Grande would be pulled back to create a fixed and stable border between the two countries.
The most recent treaty overseen by the IBWC was signed in Mexico in 1970 to resolve boundary disputes and maintain the Rio Grande and Colorado as international boundaries.
What does the US say about this incident?
On Tuesday, the U.S. Embassy in Mexico shared the Pentagon’s comments, saying a U.S. “contractor” installed signs marking “National Defense Area III” by the Rio Grande.
“Changes in water depth and topography have changed the perception of the border’s location,” the statement said. “Mexican government officials removed six signs based on their knowledge of the location of the border.”
The Pentagon added that the contractor “will work with appropriate agencies to avoid future disruptions.”
The National Defense Area (NDA) is a military zone of the United States along the U.S.-Mexico border, administered by the Department of Defense.
On May 1, the US Northern Command announced that a new 260-mile (418 km) NDA had been established along the Mexican border in southern Texas.
“The creation of the National Defense Zone increases the scope and effectiveness of our operations in deterring illegal activities along our southern border,” General Grégory Guillot, commander of Northern Command, was quoted in the statement as saying.
Where does NDA fit in?
The NDA was established under a presidential memorandum signed by President Trump in April of this year entitled “Military Mission to Close the Southern Border of the United States and Refuse Invasion.”
The order directs the Department of Defense to take a more direct role in securing the U.S.-Mexico border. This memorandum directly authorizes the Department to establish NDAs.
The U.S. Northern Command website states that the Department of Defense is enforcing a “controlled perimeter” in the NDA to “prevent mass illegal immigration, drug trafficking, migrant smuggling, human trafficking, and other cross-border criminal activity.” Suspected trespassers may be detained under non-disclosure agreements, but must then be turned over to the custody of local law enforcement.
In addition to the new NDA, there are currently three NDAs in operation in Texas, according to the website. One of them straddles Cameron and Hidalgo counties in Texas. Other locations include New Mexico and Yuma, near the California-Mexico border.
What is the broader context?
The United States has sent large military forces to the Caribbean in recent months, including B-52 bombers and elite special operations forces, citing security concerns and threats of “invasion” from Venezuelan drug cartels. President Trump is also considering a ground attack on Venezuela to curb the flow of illegal drugs, and has authorized covert CIA operations there for the same purpose.
Since September 2, the United States has carried out at least 21 military attacks against suspected Venezuelan drug smuggling vessels in the Caribbean and Eastern Pacific Ocean, killing about 80 people. Now, President Trump seems to be turning his attention to Mexico.
On Monday, President Trump threatened to launch an attack on Mexican drug cartels.
During a meeting between President Trump and FIFA President Gianni Infantino in the Oval Office, Trump told reporters: “Do we want a strike in Mexico to stop drugs? Whatever we have to do to stop drugs, that’s fine.”
“I looked at Mexico City over the weekend. There are some big problems over there.”
Sheinbaum responded to President Trump’s comments on Sunday about possible U.S. intervention in Mexico during his daily press conference Tuesday morning. “That’s not going to happen,” she said.
Sheinbaum said President Trump and Secretary of State Marco Rubio repeatedly communicated in their phone calls that Mexico does not want the United States to intervene in Mexican territory.
“He has suggested and said several times, ‘We’ll provide U.S. military intervention in Mexico and whatever it takes to fight these criminal groups,'” she explained.
Sheinbaum said he was open to cooperation and intelligence sharing with the U.S. military, but reiterated that outside interference in the country would not be tolerated.
“We do not accept interference by any foreign government,” Sheinbaum continued. “I told him on the phone. I told the State Department, I told Marco Rubio.”
