UN Secretary-General Ban Ki-moon arrived in the Japanese city of Fukushima, where he planned to visit the nuclear disaster zone around a damaged atomic power plant.
The UN chief is one of the most senior foreign officials to go near the damaged nuclear plant since the March 11 earthquake and tsunami that triggered the catastrophe.
On August 8, Ban planned to meet some of the 85,000 people who have been evacuated from areas around the plant after what has become the worst nuclear disaster since Chornobyl 25 years ago.
Also, Ban was due to meet Prime Minister Naoto Kan and Foreign Minister Takeaki Matsumoto.
Ban has convened a nuclear safety summit for the UN General Assembly in New York in September and he is expected to reinforce his calls for tougher international nuclear standards while in Japan.
compiled from agency reports