Fast Retailing Co., operator of the Uniqlo casual clothing chain, said Wednesday it will switch from plastic to paper shopping bags from September, joining worldwide efforts to tackle what many believe is one of the most pressing environmental issues.

Under the plan, the company aims to reduce the amount of plastic used for shopping bags and packaging materials at its group stores worldwide by 85 percent, or around 7,800 tons annually, by the end of 2020.

From Sept. 1, stores in Japan and other countries that have been using plastic shopping bags will switch to bags made from recycled paper and other eco-friendly materials. In Japan, shoppers will be charged ¥10 ($0.09) plus tax per bag from Jan. 14.

Stores in markets where paper bags are already in use, such as Uniqlo stores in Europe, will also start using the eco-friendly bags.

The company will start charging for shopping bags in September or later at its Uniqlo and GU stores overseas, such as those in Europe, North America and South Korea.

Fast Retailing also said it will stop using plastic packaging for some items for this fall and winter, such as room slippers, while also launching studies on ways to eliminate packaging for products such as Uniqlo's HeatTech fabric clothing.

"Environmental pollution from plastic waste is a growing concern worldwide, and Fast Retailing is taking action to reduce unnecessary single-use plastic from its operations," the company said.

Fast Retailing operates more than 3,500 stores around the world, including about 2,100 Uniqlo shops as of the end of February.