The Government Accountability Office says the plans to transform Guam into a major military hub will cost the U.S., Japan and Guam a total of $23.9 billion, Stars and Stripes reports.
The first $14 billion will come from the U.S. over the next five years for construction work and relocation of Marines as well as an Air Force compound.
Japan will pay $2.8 billion for construction. They will also loan out $3.3 billion for utility upgrades and other infrastructure work on the island.
The GAO says Guam estimates it will need about $3.2 billion in improvements to island infrastructure such as roads, electricity, hospitals, water and sewer, so it can handle about 24,000 additional residents who will come with the buildup.