Japanese Prime Minister Shinzo Abe has visited the Fukushima Daiichi nuclear plant, amid public concern over radioactive water leaks.
He ordered the plant operator to stem all the leaks within six months and gave instructions for decommissioning of two reactors.
Earlier this month, radiation levels near the plant's water tanks rose to a record high, according to officials.
The plant has been hit by several leaks in recent months.
The plant was crippled by the earthquake and tsunami in March 2011. Cooling systems for reactors were knocked out, causing meltdowns at three of them.
Water is being pumped in to cool the reactors, however this creates large amounts of contaminated water that must be stored securely.
Some of the water has leaked from the tanks, pipes, and damaged structures, leading to concerns contaminated water is mixing with groundwater that is flowing into the sea.
Mr Abe, who last visited the plant shortly after he took office in December, met representatives from plant operator Tokyo Electric Power Company (Tepco).
He inspected storage tanks holding radioactive water and water treatment equipment at the plant during his three-hour tour, reports say.
"I've urged Tokyo Electric Power Company to deal with the contaminated water leakage as its priority. I gave them three demands," he said.
These demands include earmarking discretionary funds "that managers on site can use to implement necessary safety measures".
It also includes a "deadline to complete the purification of waste water stored in tanks at the plant" and "decommissioning the idle No 5 and 6 reactors and concentrate efforts to solve problems".
The two reactors are in addition to four others that were earlier marked for decommissioning.
Earlier this month, the government pledged hundreds of millions of dollars to build a wall of frozen earth around the reactors in order to contain some leaks.
Speaking at the time, government spokesman Yoshihide Suga said the government "felt it was essential to become involved to the greatest extent possible".
During Japan's successful 2020 Olympic bid process, Mr Abe assured the International Olympic Committee that the situation at Fukushima was "under control".