Japan has approved assigning its troops in South Sudan on non-combative support under U.N. peacekeeping operations, an additional mission that opponents say would risk of getting them embroiled in international fighting that Tokyo has renounced since the end of World War II.

The task, approved Tuesday by the Cabinet, begins with a 350-troop South Sudan mission to be dispatched in three waves beginning Sunday, under Japan's new security law enacted last year.

Prime Minister Shinzo Abe's government has been expanding Japan's international military role, but opponents say the mission not only puts Japanese soldiers at greater risk but also violates Japan's pacifist constitution.

Japan has dispatched troops to war-torn South Sudan since 2011, but their operation was limited to construction projects in non-combative areas.