U.S. Defense Secretary Ash Carter says a nearly completed revision of the U.S.-Japan Defense Guidelines will transform the bilateral alliance and help the countries respond to challenges in the Asia-Pacific region and around the globe.

Carter is in Tokyo on Wednesday to meet with Japanese officials on his first trip to Asia since becoming defense secretary in February. He visits South Korea later this week.

Japan and the United States are expected to finish the revision of their defense guidelines later this month.

Japanese Defense Minister Gen Nakatani says he and Carter also reiterated their support for a controversial plan to relocate a U.S. Marines base to another part of Okinawa in southern Japan.