Russia said on Wednesday it was concerned by Japan's discharge of treated radioactive water from the wrecked Fukushima nuclear power plant and called on Tokyo to give detailed information about the process.
Japan started releasing treated radioactive water from the Fukushima plant into the Pacific Ocean last month, and faced harsh criticism from China which immediately banned all seafood imports from Japan.
Foreign Ministry spokeswoman Maria Zakharova said there had been a lack of transparency from Tokyo over the issue.
"We don't see any transparency or openness from Tokyo," Zakharova told reporters.
Zakharova said she hoped Japan would give all the necessary scientifically-based and detailed information to countries concerned by the discharge.
"We are not the only country which is expressing such concerns - China has too, and the Japanese themselves have," Zakharova said.
A massive earthquake and tsunami in 2011 triggered a nuclear meltdown at the Fukushima Daiichi power plant in the world's worst nuclear disaster since Chernobyl 25 years earlier, in what was then Soviet Ukraine.
Japan says the water release is safe, noting that the International Atomic Energy Agency (IAEA) has also concluded that the impact it would have on people and the environment was "negligible". (Writing by Felix Light; editing by Guy Faulconbridge and Gareth Jones)