The ruling Liberal Democratic Party proposed to its two coalition allies Thursday that the law be amended to expand the scope of activities of the Self-Defense Forces, coalition officials said.
The proposal is a reaction to this week's terrorist attacks on the United States.
The coalition, however, did not make an immediate decision on whether to push through the amendments during the extra Diet session slated to convene Sept. 27.
While the New Conservative Party expressed support for the idea, New Komeito was cautious, they said.
The LDP suggested revising the SDF law after the forces were unable to comply with a request from the U.S. to guard its military facilities in Japan following the attacks. The law allows only the police to conduct such activities.
A senior LDP official was earlier quoted as saying this could damage the Japan-U.S. alliance.
The LDP proposal, made during a meeting of secretaries general and Diet affairs chiefs of the three parties, also calls for the law to be revised to expand the SDF's role in protecting nuclear plants and local government facilities.
It also proposed that the coalition form legislation during the next regular Diet session, which starts in January, covering SDF actions in the event of an armed attack against Japan, the officials said.
The coalition is expected to hold further talks on the issue.
Japan has been considering emergency legislation since 1977, but no administration has attempted to introduce such laws.
The legislation is needed to allow the SDF to perform a variety of functions, such as establishing command posts or field hospitals. It is a sensitive topic particularly because it involves the expropriation of private property for military operations.