Some lawmakers of the ruling Liberal Democratic Party will set up a group to help accelerate the Japanese government's efforts to expand defense-related exports, a source close to the matter said, despite reluctance shown by its coalition partner.

The group, to be launched as early as this month, will advocate a review of the "three principles," the nation's strict guidelines on the overseas transfer of defense equipment and technology under its postwar pacifist Constitution, the source said.

The move comes after the government last month revised its key defense documents, including the National Security Strategy, a long-term policy guideline.