Sen. John McCain, chairman of the U.S. Armed Services Committee, expressed hope that the SDF will be operating in the Middle East and the South China Sea under Japan's new security policy.

The senior politician, who has a heavy influence on defense and foreign policy, also said in an interview that the Self-Defense Forces might take part in combat in the event of a contingency on the Korean Peninsula.

McCain made the comments Tuesday as Japan seeks to revise the bilateral defense cooperation guidelines in a way that allows the SDF to expand its overseas activities with the U.S. military. This revision reflects Japan's controversial security shift under Prime Minister Shinzo Abe to allow the use of collective self-defense, or coming to the aid of an ally under armed attack even when Japan itself is not under direct attack. Until last year, collective defense was considered banned under the war-renouncing Constitution.