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The head of the U.N.'s atomic watchdog says the Japanese nuclear crisis presents a major challenge and has enormous implications for nuclear power.

Yukiya Amano, head of the International Atomic Energy Agency, says the global community cannot take a "business as usual approach" and that more needs to be done to strengthen the safety of power plants to reduce the risk of future disasters such as the one at the Fukushima Dai-ichi plant that has been releasing radiation since it was hit by an earthquake and tsunami on March 11.

Amano spoke Monday at the opening session of a meeting that has drawn representatives from dozens of countries to scrutinize safety at each other's power plants.