The U.S. delegation withdrew on April 8 from ongoing meetings at the International Maritime Organization's Marine Environment Protection Committee's 83rd session, where countries are discussing imposing a fee on ships over carbon emissions through April 11, gCaptain reported on April 8. The U.S. delegation also sent a letter to embassies of other participants in the talks saying Washington would shield U.S. ships from fees and threatening unspecified "reciprocal measures."