Japan is poised to postpone a planned revision to an accord to boost its Self-Defense Forces' assistance to the U.S. military amid domestic criticism of recent defense reforms, sources close to the matter said Saturday.

The government and ruling bloc had planned to submit proposals to revise the acquisition and cross-servicing agreement, or ACSA, during an ordinary Diet session to be convened Jan. 4. The accord has allowed the troops of the two countries to share supplies and transportation services.

Japan and the United States have been in talks to have the military cooperation expand into areas such as information gathering and surveillance, antipiracy operations and defense against ballistic missiles.