The government Tuesday formally gave the green light to a plan to relocate the U.S. Marine Corps heliport now at the Futenma Air Station to the Henoko district of Nago, Okinawa Prefecture. Endorsing the project at a Cabinet meeting, the government adopted a basic policy on the relocation, including measures for local economic development. But concerning the proposed 15-year time limit on U.S. use of the base -- one of many contentious issues -- the policy merely says the government will include the issue on the agenda in its talks with the United States. Nago Mayor Tateo Kishimoto announced Monday that the city will accept the relocation plan on condition that the U.S. military use be limited to 15 years. Tokyo has said it is difficult to discuss a time limit because the life span of the base will be connected to a variety of uncertain factors, such as the future international climate. Washington has expressed its opposition to a time limit. Asked if Tokyo intends to further negotiate with Washington over the issue, Chief Cabinet Secretary Mikio Aoki repeated it will "take up" the issue in future talks because the government takes seriously the demands from Okinawa Prefecture and the city of Nago. It is not known, however, if Tokyo will begin negotiations on the time-limit issue in the next round of talks with the U.S. on the relocation plan. These discussions may come as early as next month, in line with a 1996 Japan-U.S. agreement. The government expects the talks to result in the Henoko district being officially selected as a site for the heliport before the July 21-23 summit of the Group of Eight industrialized nations in Nago. Tokyo will start talking soon with the Okinawa government and the city of Nago on what kind of base should be built and to draw up a basic construction plan, Aoki said. The relocation policy promises the central government will disburse 100 billion yen over 10 years starting in 2000 to boost the economy of northern Okinawa, including Nago. In the basic policy, Tokyo said it will take measures to minimize environmental damage from construction and to protect local residents' lives -- another condition set by Kishimoto in his announcement to accept the relocation. Also, the government pledged in the plan its efforts to enable commercial airlines to use the new facility jointly with the U.S. military -- as demanded by the prefecture. Tokyo is also considering new legislation for economic development and for promoting use of the land to be vacated following the relocation. Defense Agency Director General Tsutomu Kawara said Tuesday he would "explain" the time-limit issue to his U.S. counterpart, William Cohen, in their meeting scheduled for next month in Washington but would not "negotiate" over it. Kawara plans to visit the U.S. between Jan. 4 and 9. "The government's point of view (with regard to how and when to discuss the matter with the U.S) has yet to be formed," Kawara told reporters at the Defense Agency. Kawara is expected to reconfirm the steady implementation of a 1996 agreement between Japan and the U.S. during the defense talks slated for Jan. 7 in Washington. Regarding how to take up the issue of the 15-year time limit during talks with Washington, Foreign Minister Yohei Kono said the government has yet to specify the framework of such talks. "The government attaches great importance to the requests from the Okinawa governor and Nago's mayor," Kono told a news conference Tuesday. "The government will take up the issue in talks with the U.S. in consideration of the changes expected in the international situation." Tokyo, however, needs more time to set the framework of such talks, Kono said, adding that it will strive to reach a conclusion "as soon as possible."