"The earthquake, tsunami and the nuclear incident have been the biggest crisis. Japan has encountered in the 65 years since the end of World War Two," a grim-faced Kan had told a news conference on Sunday.
"We're under scrutiny on whether we, the Japanese people, can overcome this crisis."
A badly wounded nation has seen whole villages and towns wiped off the map by a wall of water, leaving in its wake an international humanitarian effort of epic proportions.
Officials confirmed on Sunday that three nuclear reactors north of Tokyo were at risk of overheating, raising fears of an uncontrolled radiation leak.
Engineers worked desperately to cool the fuel rods in the damaged reactors. If they fail, the containers that house the core could melt, or even explode, releasing radioactive material into the atmosphere.
Operators had earlier halted injection of sea water into the reactor, resulting in a rise in radiation levels and pressure. The government had warned that an explosion was possible because of the buildup of hydrogen in the building housing the reactor.
Japan battled through the weekend to prevent a nuclear catastrophe and to care for the millions without power or water in its worst crisis since World War Two, after a huge earthquake and tsunami that likely killed more than 10,000 people.
The government had warned of a possible explosion at the No. 3 reactor because of the buildup of hydrogen in the building housing the reactor. TV images showed smoke rising from the Fukushima facility, 240 km (150 miles) north of Tokyo. - Yahoo.News