United Nations: UN chief Ban Ki-moon, who is on a visit to the tsunami and earthquake-ravaged Japan, has said the damage at the Fukushima nuclear plant serves as a reminder that even the best-prepared nations need to improve their capacity to prevent and cope with such disasters.

Expressing the United Nations' solidarity with the people of Japan, Ban said he is "very much encouraged" with the way the Japanese government and people have been trying to "overcome with composure" and determination the unprecedented natural disaster that struck their country earlier this year.

"I believe Japan is one of the best-prepared countries in the world in terms of natural disaster, disaster risk reduction and preparedness. However, the scope of the tsunami and nuclear power accident was so great that we have to learn what needs to be done more in the future," he said in his remarks at a breakfast meeting hosted by State Secretary for Foreign Affairs Chiaki Takahashi.

Ban added that the Fukushima Daiichi nuclear power accident has "given us a great lesson, that was we need to have a review and full safety and improve our capacity for such emergency response," a UN statement said here.

Ban is expected to visit Haragama beach at Soma, about 40 kilometers north of the Fukushima plant where high radiation levels continue to pose serious hazards even five months after the tsunami and earthquake caused massive damage at the plant.

The UN chief said he was eager to meet people accommodated at evacuation centres and extend to them all possible help from the United Nations.

The earthquake and tsunami on March 11 left about 23,000 people dead or missing along Japan's northeast coast.

The Secretary General will later travel to South Korea.