The government has drafted a bill stipulating how it should respond to an attack involving nuclear, biological or chemical weapons.
The bill states that the government is responsible for combating contamination if the country comes under attack with biological or chemical weapons. This is the first such mention in proposed legislation.
Officials said the government will present the bill as early as next week to a special committee in the House of Representatives that has been scrutinizing legislation on how Japan should respond to a military attack.
The outline stipulates that the government would have a major role in protecting and rescuing civilians in the event of an attack.
According to other measures in the outline, the government would take enforcement measures if civilians do not obey official orders to contribute their supplies or allow the use of their properties.
The national government would use its budget to cover all expenditures paid by local governments in protecting Japanese nationals, the outline says.
The government would provide compensation if people die or sustain injuries in the course of helping relief activities, it says.
The bill also calls for collaboration between local governments and the Self-Defense Forces in the event of a crisis by allowing SDF officers to take part in meetings at local government emergency headquarters.