The United States and Japan have struck a bargain over a plan to realign U.S. forces in Japan, with Japan agreeing to pay $6.1 billion of the nearly $10.3 billion cost, the Japanese defense chief said Sunday night.

Japanese Defense Minister Fukushiro Nukaga told reporters after his three-hour meeting with Defense Secretary Donald H. Rumsfeld that Japan wanted to have an appropriate sharing of costs in transferring 8,000 Marines from Okinawa to the Pacific island of Guam.

Japan has offered to pay $2.8 billion, and the remainder of its $6.1 billion share would take the form of loans to the United States. Japan would shoulder 59 percent of the realignment cost.

Pentagon officials could not be reached immediately for comment on the accord.

Nukaga said both sides agreed that the Japan-U.S. alliance is important, not only for Japan but also for the region.

"I had not expected that such an agreement was possible," Nukaga told Japanese reporters, according to Japanese broadcast network NHK. "Japan and the United States were still wide apart on the issue, and I thought it won't go anywhere unless I directly meet with Mr. Rumsfeld for talks aimed at a breakthrough."

The United States had proposed in an earlier round of negotiations that Japan pay $7.5 billion, or 75 percent, of the cost to relocate Marines. Japan had said it would pay about one-third of that amount.

The United States and Japan are discussing the biggest restructuring and streamlining of the U.S. military based in Japan in decades.

An outline of the overall realignment plan was announced in October and was to be finalized by the end of March. However, it bogged down over details.

Under a mutual security pact, the United States has about 50,000 troops stationed in Japan. The presence includes more than 10,000 Marines, several air bases and the home port for the Navy's 7th Fleet.