The International Atomic Energy Agency will continue to provide assistance for member countries to prevent nuclear disasters such as those seen in Chernobyl and Fukushima, its chief said Tuesday.

IAEA Director-General Yukiya Amano made the pledge in a statement issued to mark the 30th anniversary of the accident at the Chernobyl nuclear power plant in northern Ukraine during the Soviet era.

"We remain committed to helping our member states to do everything humanly possible to ensure that accidents such as those at Chernobyl and Fukushima Daiichi never happen again," he said, referring to the 1986 Chernobyl disaster and 2011 meltdowns at the Fukushima No. 1 nuclear plant.

Amano pointed out that following the Chernobyl disaster, hundreds of thousands of people were hit by high radiation doses and some 350,000 people were forced to leave their homes in seriously contaminated areas.

"This was deeply traumatic for all concerned and had a lasting impact on their lives. Their suffering must not be forgotten," he said.

The IAEA chief also said that despite the progress made on nuclear safety since the Chernobyl accident, another major disaster occurred at Fukushima No. 1.

"This was a painful reminder that a serious accident can occur even in a technologically advanced country with a mature nuclear program," Amano said.

"The key lesson from both Chernobyl and Fukushima Daiichi for everyone involved in nuclear power — plant operators, governments and regulators — is that safety can never be taken for granted," he said. "Complacency must be avoided at all costs."