A United Nations plan to cut greenhouse gas emissions from global shipping was shelved after US President Donald Trump threatened to retaliate against countries supporting the measure, reported the Washington Post.

The International Maritime Organization (IMO) had been poised to adopt a compact requiring large vessels to reduce emissions by 17 per cent by 2028, with full decarbonisation by 2050. The plan was backed by major shipping firms and trade groups, including Maersk and the World Shipping Council.

President Trump denounced the proposal as a "Global Green New Scam Tax on Shipping," warning it would raise costs for US consumers. US Ambassador to the United Nations Michael Waltz urged nations to oppose the plan or face "serious consequences."

The US State Department warned that countries supporting the compact could face port entry bans, visa restrictions, trade probes, sanctions, and loss of US contracts. The threats, echoed by other fossil fuel producers such as Saudi Arabia, led the IMO to delay the vote for at least a year.

The decision stunned observers, including shipping scholar Salvatore Mercogliano, who said the deal had appeared certain earlier in the week. Environmental groups condemned the outcome, with the Ocean Conservancy calling it "disgraceful."

The proposed rules would have required ships to shift from heavy fossil fuels to greener alternatives and adopt carbon capture technologies. Small island nations had argued the plan was already too weak to address the climate threats they face.

The Trump administration's stance reflects a broader rejection of international climate initiatives, contrasting with the previous US administration's support. Scientists and environmental advocates have criticised the move as undermining global decarbonisation efforts.