Japan's shipments of plastic waste overseas in 2018 decreased 30 percent, figures from a research institute showed Thursday, hit by restrictions China imposed on receiving such waste in late 2017.

Japan exported about 1.01 million tons of plastic waste in 2018, down from 1.43 million tons the previous year, according to the Institute for Global Environmental Strategies, with shipments to China plunging to 100,000 tons last year from 1.02 million tons.

China, a major importer of plastic and other waste, imposed an import ban on nonindustrial plastic waste and restricted imports of industrial plastic waste in late December 2017 amid growing concerns over pollution and health problems.

Japan's plastic waste shipments to Southeast Asian nations such as Thailand, Malaysia and Vietnam increased in 2018 after China imposed restrictions.

But Japan's shipments to Southeast Asia are unlikely to grow further as some countries in the region have also started to impose restrictions.

Experts said Japan needs to take action to reduce its generation of plastic waste.

Yoshinori Morita, a visiting researcher at IGES, said the Japanese government should oblige manufacturers of plastic products to use recycled materials in Japan.

Morita also called for introducing international rules to better recycle plastic waste in Asia.

"Japan needs to take the initiative in creating common rules throughout the Asian region so that plastic waste can be recycled properly," said Morita.

Hideshige Takada, a professor at Tokyo University of Agriculture and Technology, said companies should use alternative materials for food containers and other products.