The government has begun talks with the ruling coalition on developing legislation to enable the Self-Defense Forces to protect Japanese private-sector vessels if they are attacked by armed groups on the open sea, according to government sources.

The legislation enabling the dispatch of SDF vessels or planes for the protection of private-sector ships is aimed at strengthening anti-piracy measures in the Strait of Malacca and the Indian Ocean, the sources said Sunday.

The government is expected to call for examining such legislation in its basic policy to be announced sometime this week by Prime Minister Shinzo Abe on whether Japan should exercise the right to collective self-defense and on expanded roles overseas of the SDF, according to the sources.

The government hopes to revise the SDF law at an extraordinary Diet session in the autumn to allow the SDF to protect private-sector ships on the open sea, as part of measures to deal with "gray zone" incidents that stop short of outright military attacks against Japan, the sources said.

Abe's Liberal Democratic Party and its junior coalition partner, New Komeito, plan to accelerate talks on the gray zone legislation before trying to narrow their differences over the right to collective self-defense.

New Komeito remains cautious about making such a drastic change to the nation's security policy.

Japan has the right to collective self-defense under international law, but cannot exercise it due to limits outlined in Article 9 of the Constitution.