A United States congresswoman Madeleine Bordallo says cuts to military construction projects on Guam are likely to mean less competition in the construction industry and to reduce savings in future.
The US and Japan governments have decided to set back the planned date of 2014 for relocating thousands of troops from Okinawa in Japan to the US territory.
Ms Bordallo says a report from the Government Accountability Office highlighted savings of nearly 93 million dollars on military construction projects over the last two years.
She says the savings are a direct result of a competitive construction market because of the build-up.
She says the Department of Defence needs to provide Congress with a finalised master plan so it can properly oversee the programme.