The United Nations’ shipping agency is set to adopt a plan to cut maritime emissions, but the move is under threat from the United States. The Net Zero Framework, which requires ships to reduce their carbon emissions starting in 2028 and achieve complete decarbonisation by 2050, was approved in April by a majority of members, including the European Union, Brazil, China, India, and Japan. However, the US has threatened sanctions and other punitive actions against countries that support the framework, potentially delaying its adoption.

The framework would require all ships to use a less carbon-intensive fuel mix or face financial penalties. The US had withdrawn from negotiations and did not comment on the proposal until recently, when top diplomats and secretaries stated that the administration “unequivocally rejects” the plan. They threatened a range of actions against countries that vote in favour of the framework, including visa restrictions, blocking vessels from US ports, and imposing commercial penalties.

The European Union has reaffirmed its support for the proposal, as has Britain. However, the US threats may affect other countries that are sensitive to US influence and vulnerable to retaliations. The Philippines, which has the world’s largest contingent of maritime workers and supported the framework in April, could be particularly impacted by visa restrictions. Caribbean islands that are economically dependent on US cruises could also be affected by sanctions.

The framework would charge ships a tax on emissions exceeding a certain threshold, creating a fund to reward low-emission vessels and support countries vulnerable to climate change. If adopted, the global emissions pricing system would be difficult to evade, even for the United States. The International Maritime Organization’s conventions allow signatories to inspect foreign ships during stopovers and even detain non-compliant vessels.

The US threats come as President Donald Trump has reversed Washington’s course on climate change, denouncing it as a “scam” and encouraging fossil fuel use through deregulation. The outcome of the vote on the Net Zero Framework is now uncertain, with consensus having already been ruled out. The adoption of the framework would be a significant step towards reducing maritime emissions and mitigating the impacts of climate change.