Japan is to invest hundreds of millions of dollars into building a frozen wall around the Fukushima nuclear plant to stop leaks of radioactive water.
Government spokesperson Yoshihide Suga said an estimated 47 billion yen ($NZ600 billion) would be allocated.
The leaks were getting worse and the government "felt it was essential to become involved to the greatest extent possible", Mr Suga said.
The plant was crippled by the March 2011 earthquake and tsunami.
The disaster knocked out cooling systems to the reactors, three of which melted down.
Water is now being pumped in to cool the reactors, but storing the resultant large quantities of radioactive water has proved a challenge for plant operator Tokyo Electric Power Company.
Under the government plan, a wall of frozen earth will be created around the reactors using pipes filled with coolant to prevent groundwater coming into contact with contaminated water being used to cool fuel rods.
Dr Tatsujiro Suzuki, vice chairman of the Japan Atomic Energy Commission, said the situation at the nuclear power plant was an "unprecedented crisis" and that it was getting worse.
He said the plan to freeze the ground around the site was "challenging", and a permanent solution was needed.
The technique has only been used on a small scale to control pollution before but not with radioactive contamination, Mr Suzuki added.
The damage to the plant has necessitated the constant pumping of water to cool the reactors - a process which creates an extra 400 tonnes of contaminated water every day.