The United States is committing one billion US dollars for a road that would link U.S. military facilities in northern and southern Guam.
The arrangement comes under the U.S.-Japan pact that Secretary of State Hillary Clinton signed in Japan last week.
The billion-dollar road funding is in addition to the 3.18 billion dollars, which is the U.S. share of the 10.27 billion total cost to reduce the presence of U.S. Marines in Okinawa by about half.
The pact calls for 8,000 Marines of the Third Marine Expeditionary Force as well as their 9,000 dependents to be relocated from Okinawa by 2014.
The Pacific Daily News reports that relocating Marines to Guam will cost Japan a total of 6.9 billion US dollars, of which 2.8 billion will be in direct cash contribution for facilities and infrastructure for the Marines' new Guam base, according to the agreement.