The sources told The Yomiuri Shimbun the reduction is the result of a review of a 2006 accord on the realignment of U.S. forces in Japan that originally called for the transfer of 8,000 Marines.
Formal announcement of the move is expected as early as Monday, the day when U.S. President Barack Obama delivers his fiscal 2013 budget message.
Review of the bilateral agreement is expected to be discussed during the summit meeting between Japanese Prime Minister Yoshihiko Noda and Obama scheduled for this spring.
The United States reportedly plans to separate the transfer of the 4,700 Marines from the issue of relocating the U.S. Marine Corps' Futenma Air Station in Okinawa prefecture.
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