The United Nations opened its 23rd Conference on Disarmament in Matsumoto city, central Japan, on Wednesday morning.
In a keynote speech at the start of the 3-day event, International Atomic Energy Agency chief Yukiya Amano called the accident at the Fukushima Daiichi one of the most serious and complicated crisis human beings have ever faced.
But he said nuclear power generation will continue to be an important option for many countries, and that the use of nuclear energy will increase in the decades to come.
Amano added that the IAEA will play a leading role to ensure nuclear safety.
Japan has hosted the annual disarmament conference since 1989 as the only country to have experienced atomic bomb attacks.
The focus of the event is on united actions toward a nuclear weapons-free world, including issues such as the US-Russian nuclear disarmament treaty and nuclear development in Iran and North Korea. This year, in the wake of the accident at the Fukushima Daiichi nuclear plant, participants are also discussing nuclear safety.
The conference is being attended by about 90 government officials and experts from 24 countries.