A Japanese Cabinet minister apologized on Tuesday after appearing to suggest people in nuclear disaster-hit Fukushima could be persuaded to put up with contaminated waste if the government threw cash at them.

Environment Minister Nobuteru Ishihara came under fire after saying money would be a decisive factor for local governments and residents being asked to accept plans to build storage facilities for radioactive waste.

The remarks were seen as insensitive to the tens of thousands of people who remain unable to return to homes around the crippled Fukushima nuclear power plant because of persistently high levels of radiation.

Fukushima Governor Yuhei Sato immediately hit back, saying: "It was extremely regrettable. The remarks rode roughshod over the feelings of residents who are longing for their hometowns."

Goshi Hosono, former environment minister and a senior lawmaker of the opposition Democratic Party of Japan, called for Ishihara's resignation, telling reporters: "The remarks - it's about money - should never have been made."

Ishihara said on Tuesday: "I sincerely apologize to those who were annoyed by my remarks."

He said, however, he would continue exploring proposals for waste-storage facilities, including details of compensation.

Central and local governments have been negotiating for months over the construction of "temporary" storage facilities for soil and other waste contaminated by fallout from the meltdowns at Fukushima following the 2011 tsunami.

Ishihara's gaffe was unusual for a man who has shown himself to be a relatively sure-footed politician, but was redolent of his father, current lawmaker and former Tokyo Governor Shintaro Ishihara, who is no stranger to controversy.

Just three days after Japan's northeast was swamped by the huge tsunami, Ishihara senior caused outrage by saying the disaster - which killed more than 18,000 people - had been divine punishment for a nation obsessed by materialism.

Also on Tuesday, Tokyo Electric Power, the operator of the battered Fukushima nuclear power plant, said it was having trouble with the early stages of an ice wall being built under broken reactors to contain radioactive water.

On the same day, the Cabinet of Japan approved Japan's Energy White Paper 2013, which defines nuclear power as an "important baseload power source" and calls for a return to nuclear power generation, Xinhua News Agency reported.