International nuclear regulators warned Tuesday that growing amounts of radioactive water in and around Japan's tsunami-stricken Fukushima Daichi nuclear power plant remained a threat, NBC News reported.
"The situation remains very complex, with the increasing amount of contaminated water posing a short-term challenge that must be resolved in a sustainable manner," according to a report by the International Atomic Energy Agency (IAEA).
In addition to tainted water, the plant's administrators still have to dispose of dangerous radioactive fuel, according to the report.
"The need to remove highly radioactive spent fuel, including damaged fuel and fuel debris, from the reactors that suffered meltdowns poses a huge long-term challenge," the statement added.
The 15-person IAEA team also praised Japan for trying to reduce radioactive risk and decommissioning.
"Japan has made significant progress since our previous missions. The situation on the site has improved — progressive clean-up has led to reduced radiation dose levels in many parts of the site," team leader Juan Carlos Lentijo, IAEA Director of Nuclear Fuel Cycle and Waste Technology, said in the statement.