Former Prime Minister Naoto Kan said in a videotaped message shown Monday at a symposium in New York that the crisis at the Fukushima No. 1 nuclear power plant was "one step away from the worst situation" and that catastrophe was avoided with "God's help."

As the prime minister at the time, Kan was in charge of the initial response to the triple meltdown at the plant, which was crippled by the March 11, 2011, quake and tsunami.

At the event staged by the Physicians for Social Responsibility organization, Kan drew a huge round of applause when he said, "The safest nuclear power or energy policy is to realize 'zero nuclear power.' "

"The worst-case scenario" envisaged was more nuclear reactors and spent nuclear fuel pools getting out of control, requiring the evacuation of around 50 million people, including those living in the Tokyo metropolitan area, according to Kan.

Had that been a reality, "many casualties may have resulted in the process of evacuation, and Japan consequently would not have fully functioned as a state over the long-term," Kan said.

"Nuclear arms and atomic power represent a technology in which coexistence with man is extremely difficult," he said.

He repeated his proposal for Japan to achieve a society where "ultimately, no nuclear power is used and no fossil fuels are needed" by expanding the use of renewable energies such as wind, solar and biomass.