As tension mounts in the South China Sea over the U.S. military's recent patrol challenging China's territorial claims there, speculation has centered on what action Japan may take in the region.

On Friday, Prime Minister Shinzo Abe struck a robust posture, saying in his speech at a Tokyo hotel he plans to rally international cooperation on upholding maritime rule of law during the Group of 20 summit in Antalya, Turkey, and the Asia-Pacific Economic Cooperation leaders’ meeting in Manila this month.

Some senior U.S. military and diplomatic officials have pressed Abe to dispatch the Self-Defense Forces on joint patrols with the United States in the South China Sea.