China is stepping up restrictions on the production, sale and consumption of single-use plastic products, as it seeks to tackle one of the country's biggest environmental problems.

Key points:

• Plastic bags will be banned across all cities and towns by 2022, with markets selling fresh produce exempt until 2025
• Other items such as plastic utensils from takeaway food outlets will also be phased out
• By 2025, Chinese restaurants will reduce their consumption of single-use plastic items by 30 per cent

The National Development and Reform Commission and the Ministry of Ecology and Environment issued a new policy on Sunday (local time) which will be implemented over the next five years.

The state planner said plastic bags would be banned in all of China's major cities by the end of 2020 and banned in all cities and towns in 2022.

Markets selling fresh produce will be exempt from the ban until 2025.

China is one of the world's biggest users of plastic, with vast amounts of untreated plastic waste buried in landfill or dumped in rivers.

Other items, such as plastic utensils from takeaway food outlets and plastic courier packages, will also be phased out.

By end of 2020, the restaurant industry will be banned from using single-use straws.

By 2025, towns and cities across China must reduce the consumption of single-use plastic items in the restaurant industry by 30 per cent.

Some regions and sectors will also face restrictions on the production and sale of plastic products, although it is not yet clear which geographical areas.

China also banned the importation of all plastic waste, and the use of medical plastic waste in the production of plastic.

The production and sale of plastic bags less than 0.025mm thick will also be banned, as will plastic film less than 0.01mm thick for agricultural use.

The United Nations has identified single-use plastics as one of the world's biggest environmental challenges.

China is already boosting recycling rates and is building dozens of "comprehensive resource utilization" bases to ensure more products are reused as part of its war on waste.