The ethnic majority in US territory of Guam fear the US planned influx of military personnel will swamp the original inhabitants of the island.
Washington is planning to relocate some 19,000 personnel and their families to Guam from southern Japan.
"This proposed military build-up, with our current political status, will result in the cultural and racial genocide of the Chamorro people," said Frank J. Schacher, the chairman of the Chamorro Tribe Inc, referring to the indigenous people who make a third of the present population of the island.
"It is our island, our ancestral remains, our sacred artifacts, our waters, our culture, and our right to exist as a race that would be destroyed by these intended actions," he added.
The island, east of the Philippines, was taken over by the United States in 1898 and its people are considered statutory US citizens.
Schacher, a 10-year veteran of the US Air Force, had previously warned that "by 2014, we are going to have an additional 78,000 active duty military, military dependants, civil service…. After 30 days on this island, they will be eligible to vote in any of our elections."
Some 8,000 of the troops are to be taken out of the Japanese island of Okinawa, where locals have for long protested the presence of US military personnel who are allegedly involved in crime, pollution, noise and accidents in the Japanese territory.