In brief
Mexico said on Friday that the border it shares with the United States cannot be changed by a state‑level government, citing the 1970 Treaty and the authority of the International Boundary and Water Commission. The ministry rejected Texas’s declaration that nine islands in the Rio Grande belong to the state. Mexico pledged to monitor the area and hold dialogue through established diplomatic channels.
The Mexican Foreign Ministry said on Friday that the border between Mexico and the United States cannot be altered by a U.S. state government, citing the 1970 Mexico‑U.S. Boundary Treaty and the exclusive authority of the International Boundary and Water Commission, according to Xinhua.
The statement came after the Texas General Land Office, led by Commissioner Dawn Buckingham, declared that nine islands in the Rio Grande—known as the Rio Bravo in Mexico—were property of the state of Texas. Mexico’s announcement was a direct response to that claim.
Under the 1970 treaty, the international boundary in the river follows the center line of the normal channel. That line sets which side of the river each island lies on, thereby determining sovereignty regardless of historical possession.
The treaty delegates the task of determining island ownership to the International Boundary and Water Commission, a joint body established by Mexico and the United States. The commission has the sole power to decide whether any island is on the Mexican or American side of the river, and no state‑level government can override that decision, the ministry emphasized.
In addition, the treaty forbids either side from building works that the commission finds could alter or obstruct the normal flow of the river. Mexico reiterated that it would not permit construction that would change the river’s course in a way that could shift border demarcations.
Mexico pledged to closely monitor any actions in the Rio Grande area and to continue pursuing dialogue through the established mechanisms of the treaty. The ministry said it would uphold its obligations under the agreement and refrain from unilateral actions that might influence the river’s flow.
The ministry’s statement effectively rejects any attempt by Texas or other U.S. state entities to unilaterally adjust the international boundary, though it leaves room for the commission’s eventual resolution of the islands’ status.
Uncertainties remain about how the International Boundary and Water Commission will determine the exact placement of the nine islands, how the commission will interpret the “normal channel” in light of changing river dynamics, and whether either country will adhere to new decisions that impact flood control or land use plans. Those questions, set out in the ministry’s declaration, will shape the future of the Rio Grande border dispute.
