"We have also announced our readiness to the International Committee of Red Cross and Japan's Red Cross Society," he added.
An 8.9-magnitude earthquake hit Japan on Friday triggering a tsunami that caused extensive damage.
So far 44 people have been confirmed dead an unknown number of people have been reported missing in Miyagi and Fukishima.
Japan has sent naval vessels to Miyagi prefecture where the nuclear plants have automatically shut down. The government says no radioactive leak and no damage to the plants have been reported.
Power outage has hit 4 million homes in Tokyo and surrounding areas and all train services in the capital have been halted. The city's Narita airport has also closed.
Japan's Prime Minister Naoto Kan has held an emergency meeting about the quake. Chief cabinet secretary Yukio Edano has said that the damage has been quite huge and stronger tsunamis are expected.