China could soon ramp up its screening of Japanese-produced food in light of a plan to release treated and diluted water from the Fukushima Daiichi nuclear power plant into the ocean.

China bans food imports from Fukushima and some other Japanese prefectures. It also tests samples of seafood from other parts of the country for radioactive substances.

But Chinese officials now suggest they'll begin blanket screenings of all food produced in Japan.

The head of a company that processes marine products in northern Japan is voicing concern. Exports to China account for roughly half the firm's sales.

Miyazaki Yukinori says, "I don't know what's happening. We've all benefited from exports."

Japan's fisheries ministry is getting complaints that seafood products are being held up for longer at Chinese customs. Officials say exports could become impossible because refrigerated marine products don't last long.

The impact of tougher Chinese inspections is also being felt in China. Businesspeople say Japanese products used to be abundant but have been hard to get for the past week.

A sushi restaurant in the city of Guangzhou usually gets 90 percent of its seafood from Japan. It's now having to source domestically.

Owner Ito Mitsuru says, "I asked the consulate for information, but it's not clear what's going to happen or when. This is a problem for everyone."

Japan will reduce tritium levels in the treated water to about one seventh of the World Health Organization's standard for drinking water.

A Chinese foreign ministry spokesperson defended the tighter import restrictions. Mao Ning said, "We must take responsibility for people's health and the marine environment. We have solid reasons to oppose Japan's ocean discharge and take relevant measures."

This month, the International Atomic Energy Agency released a comprehensive report that concluded Japan's plan is consistent with international safety standards.

The top government spokesperson in Tokyo says Japan wants the restrictions dropped as soon as possible.

Chief Cabinet Secretary Matsuno Hirokazu said, "The safety of Japanese food is scientifically proven. We will take every opportunity to urge China to scrap its import regulations quickly."

Japan plans to start releasing the water from the Fukushima Daiichi plant sometime this summer.