The UN atomic agency praised Japan's clean-up efforts eight months after the Fukushima nuclear disaster but said there was still room for improvement.

"A lot of good work, done at all levels, is ongoing in Japan in the area of environmental remediation," the International Atomic Energy Agency said in a final report delivered to Japanese authorities.

The agency encouraged Japan to continue its remediation efforts, taking into account IAEA advice following a recent fact-finding mission to the area led by Juan Carlos Lentijo from Spain's nuclear regulatory authority.

"In the early phases of the Fukushima Daiichi accident, a very cautious approach was adopted by the Japanese authorities in terms of dealing with the handling of residue materials. It is considered right to do so," Lentijo said.

"However, at this point in time, we see that there is room to take a more balanced approach, focusing on the real priority areas, classifying residue materials and adopting appropriate remediation measures on the basis of the results of safety assessments for each specific situation," he said.

A huge earthquake and tsunami on March 11 knocked out crucial cooling systems at the Fukushima plant, sending multiple reactors into meltdown and leaking radiation in the world's worst nuclear accident since Chernobyl in 1986.

The full report can be found at: http://www.iaea.org/newscenter/focus/fukushima/final_report151111.pdf