The Japanese government has formally asked the United States for help in cooling the nuclear reactors damaged by a major earthquake last week, the Nuclear Regulatory Commission said on Monday.
The commission said it is responding to the request and may provide Japan with technical advice.
A massive earthquake and tsunami battered Japan late last week, killing at least 10,000 people and triggering a crisis at three of the nation's nuclear reactors.
Japanese officials are scrambling to cool the three reactors damaged in the disaster and trying to avert a major meltdown.
The commission has already sent to Japan two agency officials with expertise in boiling water nuclear reactors, as part of a U.S. International Agency for International Development team.
USAID is a federal agency that helps countries dealing with disaster.