US Lawmakers Push to Tie Water Treaty Compliance to USMCA Review

US lawmakers are urging the Trump administration to use the USMCA review as leverage to secure Mexico’s compliance with the 1944 Water Treaty. While no formal proposal has been made to include water obligations in the agreement, the move signals that bilateral water disputes could become part of broader North American trade negotiations.

US President Donald Trump’s administration is facing growing pressure from Republican lawmakers to make Mexico’s compliance with the 1944 Water Treaty part of the ongoing review of the USMCA, signaling that water management could become a new point of leverage in North American trade negotiations.

During a Senate Finance Committee hearing on July 22, US Trade Representative (USTR) Jamieson Greer said the administration would take a broad view of the bilateral relationship as it renegotiates the trade agreement with Mexico. Responding to questions from US Sen. John Cornyn, Greer stated that President Trump would have difficulty accepting revisions or renewal of the agreement if Mexico was not “playing ball across the board,” adding that the 1944 Water Treaty was one of the issues under consideration. The comments marked the clearest indication yet that water deliveries could become intertwined with trade discussions.

Trump recently declined to automatically extend the USMCA for another 16 years, triggering the agreement’s mandatory review process and opening negotiations that could continue into 2027. At the same time, Washington has intensified pressure on Canada through new tariff threats while pursuing separate negotiations with Mexico and Canada, raising questions about the future of the trilateral framework.

Water Becomes a Strategic Trade Issue

Cornyn has been one of the leading advocates for linking trade negotiations to Mexico’s water obligations. Since January, the Texas senator has urged Greer to use the USMCA review process to secure compliance with the 1944 Water Treaty, arguing that persistent water shortages have harmed farmers and communities in South Texas.

According to Cornyn, Mexico’s fulfillment of its treaty commitments should be treated as an essential component of the broader bilateral relationship rather than as a separate diplomatic issue. His office has repeatedly argued that Washington should use the leverage provided by the USMCA review to encourage long-term compliance. 

The 1944 Water Treaty governs the allocation of water from the Rio Grande and Colorado River between Mexico and the United States. While the United States delivers water from the Colorado River to Mexico annually, Mexico fulfills its obligations through five-year delivery cycles from tributaries of the Rio Grande.

Earlier this month, Mexico and the United States reached an agreement aimed at improving treaty compliance before the current cycle expires. The agreement establishes additional measures to increase Mexican water deliveries while expanding bilateral cooperation on drought management and long-term water planning.

MBN previously reported that the agreement helped ease immediate diplomatic tensions while creating a framework for continued technical cooperation between both governments. However, Greer’s comments suggest that congressional leaders increasingly view trade negotiations as an additional mechanism to ensure compliance.

Mexico Opposes Linking Water and Trade

Mexico has previously rejected efforts to connect the 1944 Water Treaty with the USMCA. President Claudia Sheinbaum said in April 2026 that the water dispute should not be included in the trade agreement’s renegotiation. She argued that the treaty has its own bilateral mechanisms and institutions for addressing water deliveries, drought, and accumulated deficits, reportsMBN.

The Mexican government’s position is that water obligations should continue to be managed through the International Boundary and Water Commission, known in Mexico as CILA, rather than through commercial negotiations.

Sheinbaum’s comments followed earlier pressure from US lawmakers representing Texas, who argued that the upcoming USMCA review offered Washington an opportunity to demand stronger compliance.

Previous Tariff Threats 

The possibility of using trade measures to enforce the treaty is not new. In December 2025, Trump threatened to impose a 5% tariff on Mexican products unless Mexico increased its water deliveries to the United States, reports MBN.

The comments demonstrated the administration’s willingness to use tariffs to pursue objectives extending beyond conventional trade disputes. It also established a precedent for treating Mexico’s treaty obligations as an economic and commercial issue rather than solely a matter of binational water management. At the time, Trump accused Mexico of failing to deliver the volumes required under the treaty and argued that the shortfall was damaging agricultural production in Texas.

Mexico attributed the deficit partly to prolonged drought, lower reservoir levels and declining water availability in northern states. Mexican officials also warned that accelerated deliveries could place additional pressure on farmers and urban water systems in areas already facing scarcity.

Although the proposed 5% tariff was not immediately implemented, it raised concerns that water could become another recurring source of commercial uncertainty between Mexico and the United States.