TOKYO (AP) — The U.S. and Japan announced Tuesday that Washington will give back to the Japanese government nearly 10,000 acres of land on Okinawa that U.S. Marines use for jungle warfare training.

The giveback, to be completed by Dec. 22, has been in the works for 20 years and is the largest by U.S. forces in Japan since the U.S. returned control of Okinawa in 1972.

Carter announced the plan at a joint appearance with Prime Minister Shinzo Abe, who also mentioned his earlier announced plan to visit Pearl Harbor in Hawaii in late December to mark the 75th anniversary of Japan's attack.

Speaking through an interpreter, Abe said his visit to Pearl Harbor is meant to serve as a message that, "We must never again repeat the devastation of war." Carter called the visit a sign of both countries' "commitment to peace and also to reconciliation."