TOKYO, Dec. 21 (Xinhua) -- Over half of U.S. military northern training area in southern Japan's Okinawa will be returned to Japanese control on Thursday, announced Japan and the United States on Wednesday.

The U.S. will return to Japan about 4,000 hectares of land of the U.S. military training area on Okinawa's main island, announced Japanese Prime Minister Shinzo Abe and U.S. Ambassador to Japan Caroline Kennedy.

Kennedy said the land return "demonstrates our continuing commitment to reducing our impact on the citizens of Okinawa while maintaining our deterrence commitment to the entire nation of Japan."

The handover of about 4,000 hectares at the site was agreed by Japan and the United States in 1996, with a prerequisite of the relocation of helipads in the training area. The construction of new helipads was completed in mid-December.

The land return came as the U.S. military in Japan resumed use of its Osprey planes Monday afternoon, less than a week since a major accident occurred off Okinawa.

Worried about safety, local people, however, want the U.S. aircrafts to keep grounded, while the local government has urged the central government to forbid the resumption of Osprey flight operations.

Okinawa Governor Takeshi Onaga decided to absent himself from Thursday's land return ceremony and to attend a citizens' rally on Thursday to protest against central government's decision on the Osprey issue.

The Japanese and U.S. governments have been seeking to move the Futenma base from Ginowan to the less-populated Henoko coastal area of Nago.

However, the people of Okinawa, on safety concerns, have been demanding the Futenma base to be relocated outside the prefecture.