Japan's government has again met severe local opposition when proposing a site for permanent disposal of ash and mud exposed to radiation from last year's nuclear plant accident.

Senior Vice Environment Minister Katsuhiko Yokomitsu met Ibaraki Governor Masaru Hashimoto and Takahagi Mayor Yoshio Kusama separately on Thursday, to seek their cooperation on the matter.

Yokomitsu suggested a national forest in Takahagi City for the site, saying the forest has enough space and is far from residential areas.

He asked the mayor for a chance to explain the proposal to local residents, saying his ministry will ensure safety of the disposal facility.

Mayor Kusama voiced firm opposition, criticizing the government for abruptly reporting the decision without consultation during the selection process.

Earlier this month, the ministry triggered similarly strong opposition when it proposed a national forest in Yaita City in Tochigi Prefecture as a disposal site for the prefecture's own contaminated ash and mud.

The government plans to dispose of ash and mud with radioactive cesium levels of more than 8,000 becquerels per kilogram within each prefecture. The government allows waste below the 8,000 mark to remain in landfills.

A similar selection process is underway for other prefectures, but the ministry is not revealing candidate sites for fear of possible confusion in communities.

The government says it hopes to win local consent and start building a disposal facility next summer.