Residents living between 20 and 30 km from the wrecked Fukushima No. 1 nuclear power plant are being urged to "voluntarily evacuate" amid difficulties in obtaining daily necessities and the possibility of further radiation leaks, Chief Cabinet Secretary Yukio Edano said Friday.

While stressing that current radiation levels in the area do not necessitate immediate evacuation, Edano said notices have been sent out to municipalities asking them to be ready to work closely with the central and regional governments in the event an evacuation order is issued.

"With the lack of business and logistics, people's lives are becoming increasingly difficult within the 20 to 30 km radius, and we cannot rule out the possibility that more radioactive material might leak and an evacuation order be issued," he said. "Based on this situation, municipalities need to expedite their living support and voluntary evacuation of residents, as well as prepare for a scenario in which an immediate evacuation order is issued."