China will participate in international efforts to combat plastic pollution and build on its existing policies to cut waste, the environment ministry of the world's top producer said on Wednesday, a week before talks on a new global plastic pact.

More than 100 countries will meet in Nairobi next week to discuss a treaty aimed at tackling plastic pollution, with some calling for production caps as well as commitments to phase out more single-use plastic products.

China has introduced punishments and...