The United States has threatened to use visa restrictions and sanctions to retaliate against nations that vote in favor of a plan put forward by a United Nations agency to reduce planet-warming greenhouse gas emissions from ocean shipping.

UN member nations are scheduled to vote next week on the Net-Zero Framework proposed by the International Maritime Organization (IMO) to reduce global carbon dioxide gas emissions from the international shipping sector, which handles around 80 percent of world trade and accounts for close to 3 percent of global greenhouse gases.

Large container carriers, under pressure from investors to fight climate change, generally agree that a global regulatory framework is crucial to speeding up decarbonisation. Still, some of the world's biggest oil tanker companies said they had "grave concerns" about the proposal.

"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," US Secretary of State Marco Rubio, Energy Secretary Chris Wright and Transportation Secretary Sean Duffy said in a joint statement.

The "proposal poses significant risks to the global economy and subjects not just Americans but all IMO member states to an unsanctioned global tax regime that levies punitive and regressive financial penalties," they said.

Without global regulation, the maritime industry would face a patchwork of regulations and increasing costs without effectively curbing climate-warming greenhouse gas emissions, supporters of the IMO proposal have said.

The United States is considering retaliation against countries that support the plan, the US officials said in Friday's statement.

That includes potentially blocking vessels flagged in those nations from US ports, imposing visa restrictions and fees, and slapping sanctions on officials "sponsoring activist-driven climate policies". (Reuters)