The first revision of the U.S.-Japan Defence Guidelines in 17 years will "transform" the bilateral alliance, Ash Carter said.

The first revision of the U.S.-Japan Defence Guidelines in 17 years will “transform” the bilateral alliance, U.S. Defence Secretary Ash Carter said on Wednesday.

The guidelines, expected to be formally approved in about three weeks, “will help us respond flexibly to the full scope to the challenges we face, both in the Asia-Pacific and around the globe,” he said at a news conference after meeting his Japanese counterpart in Tokyo.

Mr. Carter, who travels to South Korea later this week, is on his first trip to Asia since becoming Defence Secretary in February.

Japanese Defence Minister Gen Nakatani said that he and Mr. Carter also agreed that relocating a U.S. Marines base in Okinawa to another part of the island is the “only solution” to closing the existing base, which lies in a heavily populated area.

Many in Okinawa, and their current governor, oppose the construction of the replacement base in a less populated area, arguing that the facility should be moved off Okinawa entirely.