WASHINGTON, D.C.: The United States warned it could impose visa restrictions, port bans, and sanctions on countries that back a United Nations plan to curb greenhouse gas emissions from global shipping, escalating tensions ahead of a key vote on maritime climate policy.

U.N. member states are set to vote next week on the International Maritime Organization's (IMO) Net-Zero Framework, a proposal to reduce carbon dioxide emissions from the shipping industry. The industry moves about 80 percent of world trade and produces roughly three percent of global greenhouse gases.

The Trump administration—facing domestic pressure over energy prices and global trade—said it "unequivocally rejects" the proposal, arguing that it would impose what it called an "unsanctioned global tax regime" on member countries.

"The Administration unequivocally rejects this proposal before the IMO and will not tolerate any action that increases costs for our citizens, energy providers, shipping companies and their customers, or tourists," U.S. Secretary of State Marco Rubio, Energy Secretary Chris Wright, and Transportation Secretary Sean Duffy said in a joint statement.

They warned that the plan "poses significant risks to the global economy and subjects not just Americans but all IMO member states to punitive and regressive financial penalties."

The U.S. officials said Washington is considering retaliatory measures against U.N. member nations that vote in favor of the plan. Potential actions include blocking ships registered under those countries' flags from entering U.S. ports, imposing visa restrictions or additional fees, and sanctioning officials deemed to be "sponsoring activist-driven climate policies."

The IMO proposal is designed to create a global framework for cutting emissions from international shipping, including potential levies on fossil fuel use and incentives for cleaner technologies such as green methanol and ammonia-based fuels. Proponents argue that without coordinated global rules, the industry faces a confusing patchwork of national regulations that could raise costs while failing to meet climate goals.

Large container shipping companies have generally supported a unified global standard, saying it would help them invest confidently in decarbonization. However, several major oil tanker operators have voiced "grave concerns" over the proposed framework, arguing that higher costs would hurt trade and disproportionately impact developing economies.

The U.S. stance sets up a potential clash with the European Union, several Pacific island nations, and environmental groups, all of which back the IMO framework as a necessary step toward meeting the Paris Agreement's 1.5 degrees Celsius target.

The dispute underscores the growing divide between countries prioritizing climate action and those warning of economic fallout. Supporters of the IMO plan say global shipping must act quickly to decarbonize, while opponents—led by the U.S.—see the proposal as a costly overreach that could disrupt trade and fuel inflation.

The outcome of next week's vote at the IMO headquarters in London could determine whether the world's shipping industry embarks on its most ambitious climate overhaul yet—or sails into another round of geopolitical turbulence.