Tokyo Electric Power Co. Chairman Tsunehisa Katsumata told reporters restoring stable cooling to the four earthquake- and tsunami-damaged reactors was likely to take three more months, the Kyodo news agency reported.
He said the next major hurdle would be a substantial reduction in the release of radiation by placing caps over the damaged reactors northeast of Tokyo, which could take as long as nine months, the report said.
Katsumata also said he is considering offering his resignation as a form of atonement for the nuclear crisis.
U.S. Secretary of State Hillary Clinton met with Foreign Minister Takeaki Matsumoto, the news agency said. Afterward, Clinton said the United States will continue to provide "steadfast" support to Japan in recovery and rebuilding efforts on the island nation where entire communities were shaken down and washed away in the March 11 disaster,
Some 13,500 people are confirmed dead and more than 14,700 others are unaccounted for, national police say.