The Japanese prime minister says it will take decades to clean up and decommission the Fukushima nuclear plant crippled by an earthquake and tsunami earlier this year.
The BBC says Naoto Kan made his comments at a meeting of the governing party. It was the first time the government has indicated a timeframe for bringing the nuclear crisis at the plant to an end.
Mr Kan said it would take three, five or 10 years to bring Fukushima under control and several decades to, as he put it, take care of the accident.
The public broadcaster NHK says it has obtained a blueprint drawn up by the government and the plant's operator Tepco for decommissioning the reactors.
That document gives the tentative date for beginning to remove the melted fuel rods from the reactors as 2021, as long as the necessary technology to undertake that has been developed by then.
When the disaster in March knocked out power to Fukushima, three reactors suffered meltdowns.