NHK has learned that the mayor of a southwestern Japanese city intends to decide not to take part in the first stage of a government process to select a final disposal site for high-level radioactive waste.

The city assembly of Tsushima in Nagasaki Prefecture earlier this month adopted a petition calling for the city's acceptance of a so-called literature survey. Ten assembly members voted in favor and eight against.

But Mayor Hitakatsu Naoki has the final say on accepting the survey.

He now appears to have concluded that it will be difficult to gain the wide understanding of local residents as opinions are divided over the survey.

A Japanese law calls for high-level radioactive waste from nuclear plants to be buried in a final disposal site built more than 300 meters underground.

The government is conducting a selection process in three stages to choose a site.

Hitakatsu is expected to announce his decision at the assembly on Wednesday.