TOKYO, Sept 6 (Reuters) - Japanese Prime Minister Fumio Kishida said on Wednesday he explained Japan's stance on the release of treated radioactive water from the Fukushima nuclear plant to Chinese Premier Li Qiang on the sidelines of a regional meeting in Indonesia.

Japan started releasing the water from the wrecked plant into the ocean last month, drawing strong criticism from China. In retaliation, China has imposed a blanket ban on all aquatic imports from Japan.

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.

Kishida told reporters he spoke briefly with Li ahead of a session at the Association of Southeast Asian Nations (ASEAN) in Jakarta.

"During the chat, I explained Japan's position on the treated water to Premier Li," Kishida said. He refused to say how Li had responded.

Kishida avoided commenting directly on whether he had sought the ban on aquatic imports to be lifted during his talk with Li, repeating that he had explained Japan's position. He added nothing had been decided on whether he would talk with Li again on the sidelines of the Group of 20 (G20) summit later this week.

The talk with Li marked the first time the two had met in person, Japan's foreign ministry said. It was also the first high-level talk between the two countries since the release of the water from the Fukushima plant.

A visit to China by the head of Japan's junior coalition party in late August was postponed amid worsening relations between Tokyo and Beijing following the water release.

The water is treated to remove most radioactive elements except for tritium, a radionuclide difficult to separate from water, and then diluted to internationally accepted levels before being released into the ocean.