A proposed United Nations plastic waste treaty must consider putting restrictions on the most problematic plastics, Japan's lead negotiator has said, marking the first time the country has suggested it would support curbs on plastic production.

Studies have shown that plastic output must be curbed to rein in skyrocketing plastic pollution, which is clogging waterways, despoiling oceans and killing wildlife. But such measures had been expected to face resistance from countries like Japan that are major producers of the petrochemicals in plastic.

The first round of treaty negotiations is taking place this week in Uruguay, with the agreement — described by the U.N. as the most significant green deal since the Paris climate accord — expected to be finalized by 2024.