Whitehouse Leads 21 Senate Democrats in Demanding Strengthened Environmental Provisions, Enforcement in USMCA Joint Review

Washington, D.C. - U.S. Senator Sheldon Whitehouse (D-RI), Ranking Member of the Senate Environment and Public Works Committee and a senior member of the Finance Committee, was joined by 20 Senate Democrats in sending a letter yesterday to United States Trade Representative Jamieson Greer urging the Trump administration to strengthen and better enforce environmental standards during the upcoming Joint Review of the U.S.-Mexico-Canada Agreement (USMCA).

Since USMCA's enactment, outsourcing to Mexico has continued, U.S. manufacturing jobs have declined, and the trade deficit with both Mexico and Canada has gone up. The agreement was also a missed opportunity to battle climate change and reduce pollution while creating a fairer playing field for U.S. businesses and workers. The upcoming Joint Review is an opportunity for Congress and the Trump administration to improve the USMCA to better support job creation and economic growth, boost clean manufacturing in the United States, and take steps to tackle the climate crisis.

"As the Joint Review of the USMCA approaches, we urge you to significantly strengthen the environmental chapter and ensure its robust enforcement. We agree with you that 'a rubberstamp of the Agreement is not in the national interest.' The current environmental chapter enables environmental arbitrage, which puts U.S. businesses and workers at a disadvantage, encourages offshoring, and threatens our clean air and water. It has also never been adequately enforced. Strengthening the environmental chapter cannot be done by the Administration alone - it will require Congressional action - and we stand ready to work with you," wrote the senators.

"USMCA's inadequate environmental commitments and weak enforcement force U.S. businesses to compete on an unfair playing field. Their competitors in foreign countries are effectively subsidized by being able to pollute for free," added the senators.

In addition to Whitehouse, the letter was signed by U.S. Senators Tina Smith (D-MN), Elizabeth Warren (D-MA), Martin Heinrich (D-NM), Cory Booker (D-NJ), Michael Bennet (D-CO), Ed Markey (D-MA), Andy Kim (D-NJ), Tammy Duckworth (D-IL), Jeff Merkley (D-OR), Chris Van Hollen (D-MD), Jack Reed (D-RI), Ben Ray Lujan (D-NM), Dick Durbin (D-IL), Richard Blumenthal (D-CT), Bernie Sanders (I-VT), Tammy Baldwin (D-WI), Brian Schatz (D-HI), Peter Welch (D-VT), Mazie Hirono (D-HI) and John Fetterman (D-PA).

The senators urged the Trump administration to strengthen and enforce USMCA's environmental chapter by:

• Creating a rapid response environmental enforcement mechanism;
• Strengthening commitment to combat plastic pollution;
• Fully eliminating Investor-State Dispute Settlement (ISDS);
• Harmonizing emissions reporting to strengthen U.S. business advantages in international markets;
• Closing loopholes and making environmental obligations fully binding; and
• Strengthening commitments to comply with multilateral environmental agreements.

Sierra Club, AFL-CIO, UAW, Public Citizen, BlueGreen Alliance, and NRDC also endorsed the letter.

Full text of the letter is below and a PDF is available here.

March 16, 2026

Ambassador Jamieson Greer

United States Trade Representative

Executive Office of the President

600 17^th Street NW

Washington, DC 20508

Dear Ambassador Greer:

As the Joint Review of the U.S.-Mexico-Canada Agreement (USMCA) approaches, we urge you to significantly strengthen the environmental chapter and ensure its robust enforcement. We agree with you that "a rubberstamp of the Agreement is not in the national interest."^[1] The current environmental chapter enables environmental arbitrage, which puts U.S. businesses and workers at a disadvantage, encourages offshoring, and threatens our clean air and water. It has also never been adequately enforced. Strengthening the environmental chapter cannot be done by the Administration alone - it will require Congressional action - and we stand ready to work with you.

USMCA's inadequate environmental commitments and weak enforcement force U.S. businesses to compete on an unfair playing field. Their competitors in foreign countries are effectively subsidized by being able to pollute for free. For example, a single steel company in Monterrey, Mexico reported releasing more toxic lead into the air than all companies combined in the New York/New Jersey metropolitan area.^[2] That encourages environmental arbitrage, where companies offshore American jobs to take advantage of the lower standards.

You have stated that the "successful resolution" of the Joint Review will "depend on" improvements, including to "environmental law enforcement." ^[3] One glaring example of the

the failure to enforce USMCA's environmental commitments is not holding Mexico accountable for illegal fishing. It has been four years since the U.S. requested consultations with Mexico about illegal fishing and trafficking of the totoaba fish, which threatens the survival of critically endangered vaquita porpoises that are frequently trapped in totoaba fishing nets. Enforcement action has yet to be taken. Meanwhile, as few as six members of the vaquita species remain^[4] and the Mexican fishing industry continues to reap illegal profits.

To fix the USMCA environmental chapter, we encourage a series of reforms:

• Create a rapid response environmental enforcement mechanism. The USMCA made great strides towards enforcing labor commitments by creating a Rapid Response Mechanism (RRM) for labor violations. There should be a similar mechanism for environmental violations. It should be facility-specific like the labor RRM but allow for escalation to company-wide enforcement for repeat violations to ensure gains throughout the economy. It must also be adequately funded and staffed, subject to penalties for failure to do so.
• Strengthen commitment to combat plastic pollution. An estimated eight million metric tons of plastic ends up in the ocean each year.^[5] USMCA was the first trade agreement to include language addressing plastic pollution, but it has led to little action and should be strengthened and enforced. Additionally, language should be expanded to include inadequate waste management systems, and plastic pollution throughout the lifecycle of plastics, not only "marine litter."
• Fully eliminate Investor-State Dispute Settlement (ISDS). ISDS allows extra-judicial international tribunals to order governments to pay taxpayer funds to foreign corporations. The process gives foreign multinational companies special rights and treatment in legal disputes not available to domestic companies and citizens under domestic law. Former U.S. Trade Ambassador Robert Lighthizer likened it to the U.S. government providing "political risk insurance" for multinational corporations that want to invest abroad, encouraging outsourcing.^[6] USMCA took the important step of eliminating ISDS between the U.S. and Canada and substantially limiting it between the U.S. and Mexico. However, certain U.S. oil and gas companies operating in Mexico are still able to exploit it and pressure the country against enforcing and elevating its environmental standards.
• Harmonize emissions reporting to strengthen U.S. business advantages in international markets. Many countries, including members of the European Union and the United Kingdom have created Carbon Border Adjustment Mechanisms (CBAMs), which impose tariffs on high-carbon intensity products. Since U.S. companies produce fewer emissions than foreign competitors like those in China, harmonized carbon intensity reporting for steel, aluminum, and other products will boost our industrial competitiveness. A harmonized system for monitoring, verifying, and reporting by industrial facilities should include greenhouse gas emissions and other pollutants like particulate matter and nitrogen oxides. This will demonstrate the U.S. comparative advantage globally and prevent other countries from applying unwarranted pollution tariffs to U.S. exports.
• Make environmental obligations fully binding and close loopholes. Language in the environmental chapter like "shall strive to ensure" should be replaced by binding language like "shall ensure" - similar to other chapters - to ensure the Parties follow through on their commitments. In addition, requirements that environmental violations be "sustained and recurring" and "in a manner affecting trade or investment" should be stricken. This language allows corporations to delay and undermine enforcement.
• Strengthen commitments to comply with multilateral environmental agreements. When our trading partners fail to comply with their multilateral environmental obligations, it puts U.S. businesses on an unfair playing field. NAFTA originally included a "grandfather clause" requiring Parties to comply with their obligations even when they conflict with other USMCA rules. Similar language is needed to prevent Parties from providing unfair subsidies in the form of lower standards than those U.S. companies must meet.

These reforms will be good for U.S. businesses, workers, consumers, and our environment. Many of these changes necessitate updating the text of the agreement and implementing legislation, which will require Congressional approval. We look forward to working with you to make that happen and expect robust consultation with Congress throughout the process.

[1]Office of the United States Trade Representative, "Opening Statement for House Ways and Means and Senate Finance Committees," Jamieson Greer, December 2025, https://ustr.gov/sites/default/files/files/Press/Releases/2025/Ambassador%20Greer%20Reported%20to%20Congress%20on%20the%20Operation%20of%20the%20USMCA.pdf

[2] The Guardian, "Revealed: Mexico's industrial boomtown is making goods for the US. Residents say they're 'breathing poison'," Erin McCormick and Verónica García de León, December 2, 2025, https://www.theguardian.com/us-news/2025/dec/02/monterrey-mexico-air-quality-industrial-pollution

[3] Id.

[4] The New York Times, "The Most Endangered Marine Mammal Still Exists. Here's the Latest Count.," Catrin Einhorn, June 11, 2024, https://www.nytimes.com/2024/06/11/climate/vaquita-porpoise-survey-mexico.html

[5] National Oceanic and Atmospheric Administration, "A Guide to Plastic in the Ocean," https://oceanservice.noaa.gov/hazards/marinedebris/plastics-in-the-ocean.html

[6] U.S. House Committee on Ways and Means, "W&M Holds Hearing with USTR Ambassador Lighthizer," March 22, 2018, https://waysandmeans.house.gov/2018/03/22/wm-holds-hearing-ustr-ambassador-lighthizer/