THE UN's International Maritime Organisation (IMO) member states' delegates have agreed to a global fuel emissions standard for shipping and will tax ships that breach it, Reuters reports.

Countries still need to give final approval at an IMO meeting in October.

But the US pulled out of the climate talks at the International Maritime Organisation in London, urging other countries to do the same and threatened to impose "reciprocal measures" against any fees charged on US ships.

This is an area of commerce in which Americans have less to say because only 0.2 per cent the world's commercial cargo carrying fleet is US-flagged.

Thus, it was no surprise a majority of countries approved the CO2-cutting measures to help meet the IMO's target to cut net emissions from international shipping by 20 per cent by 2030 and eliminate them by 2050.

Under the scheme, from 2028 ships will be charged a penalty of US$380 per tonne on every extra tonne of CO2 equivalent they emit above a fixed emissions threshold, plus a penalty of $100 a tonne on emissions above a stricter emissions limit.

The European Commission called the deal "a meaningful step" towards achieving the goals of the Paris Agreement on climate change, while noting it does not yet ensure the sector's full contribution to them.