Japan's huge stockpile of nuclear material and its imbalance between supply and demand pose proliferation and safety threats, Chinese experts said, adding that the international community has every reason to be concerned about Tokyo's possible nuclear ambitions.

Xia Liping, head of the Institute of International and Public Affairs of Tongji University in Shanghai, said that "unfortunately, Tokyo has done little to address these concerns".

According to data from the International Atomic Energy Agency, Japan has nearly 1,200 kilograms of highly enriched uranium and 47.8 metric tons of highly sensitive separated plutonium, of which 10.8 metric tons are stored in Japan-enough to make 1,350 nuclear warheads.