Guam's deputy speaker says a deal relocating US troops from Japan's Okinawa to Guam is premature.
US Secretary of State, Hillary Clinton, has held talks with top leaders in Japan where they signed the deal to relocate the 8000 marines plus their families by 2014.
Benjamin Cruz says the territory will need to upgrade its port, roads, and power and water systems to cope with such an influx of people.
Mr Cruz says it'll also mean a loss of land.
"On the Guam side, if this is in fact elevated to a treaty of the US, they may just say: 'we've agreed to move and we're going to provide anything that the marines want and if it'll mean an additional 1000 acres then we'll take it, whether you like it or not'."
Benjamin Cruz says the territory has introduced legislation to clear the way to survey its population on whether it supports the buildup.