The situation at the Fukushima plant is currently out of control, says Professor Christopher Busby from the European Committee on Radiation Risks, who gave RT his insight into the recent developments in Japan.

“I believe personally that it’s a global problem – and not the Japanese government’s problem only,” he added.

Earlier on Tuesday, Japan's Prime Minister Naoto Kan said that his government was determined to "take responsibility" for Japan's crippled nuclear plant "right to the end" as the operator of the plant said a revised roadmap to resolve the crisis would stick with the existing timeline.

Speaking to the media on Tuesday, Tokyo Electric Power Co. Vice President Sakae Muto said the operator would maintain the revised plan but will add new tasks, such as boosting preparedness for tsunamis and improving conditions for workers.

Reports say there are signs that two further reactors, Nos. 2 and 3, at Japan's troubled Fukushima plant may have gone into meltdown. Earlier it was confirmed that similar problems had occurred at the number one reactor during the first 16 hours following the plant’s being hit by the earthquake and tsunami.