Director General of the International Atomic Energy Agency (IAEA) Yukia Amano said Friday in Vienna that nuclear power is safer than it was a year ago but the safety must never be taken for granted.

"Nuclear safety is stronger than it was a year ago," Amano said in a statement issued ahead of the first anniversary of the Fukushima nuclear accident on Sunday.

He said that although the Fukushima nuclear accident was caused by a massive force of nature, there was weakness of design against natural hazards, accident management and emergency response.

"The accident was a jolt to the nuclear industry, regulators and governments ... we know what went wrong and we have a clear course of action to tackle those causes - not only in Japan, but anywhere in the world," he said.

Countries around the world are searching out the weak links in their own systems, and taking action to strengthen them, he added.

He also said that earlier assumptions about plant safety in the face of extreme conditions had been scrutinized and revised and defenses were being strengthened.

VietNamNet/Xinhuanet