The ministry-appointed experts said at a meeting on Friday their call for information disclosure on the basic waste disposal policy has fallen on deaf ears.
They also said that holding sessions behind closed doors could have a negative impact on the issue.
The government decided in May to select prospective sites for burying high-level radioactive waste from nuclear power plants and to ask local authorities for their cooperation in building the facilities.
The new policy was implemented following 13 years of failed efforts to solicit candidate sites due to strong safety concerns.
The ministry said it decided to hold closed-door briefings so that local government officials would feel free to speak out.
The ministry had held briefings in 39 prefectures by the end of June. They were attended by nearly 70 percent of local authorities nationwide. But some refused to attend to protest the closed-door policy.
The head of the panel, Hiroya Masuda, said the ministry must convince local authorities that the briefings don't necessarily indicate candidacy for waste disposal sites.