A flagship EU environment policy, dubbed a "carbon tax" on imports, is one of the sticking points at the UN climate negotiations in Belem, Brazil.

"This is something we do need to pursue. Pricing carbon is something that we need to pursue with as many as possible, as quickly as possible," Wopke Hoekstra, the European commissioner for climate, told the gathering.

China, India and other allied countries want COP30 to adopt a decision against unilateral trade barriers -- a dig at the European Union's Carbon Border Adjustment Mechanism (CBAM).

Tested since 2023 and set to become fully operational in 2026, CBAM targets imports of carbon-intensive goods such as steel, aluminum, cement, fertilizers, electricity and hydrogen.

The mechanism is designed to level the playing field for European industries subject to strict emissions rules.