The American Samoa Department of Marine and Wildlife says it will strongly oppose any application to clear prime rainforest.
The Congregational Christian Church has applied to clear more than 2 hectares of rainforest in the west of the territory's main island, Tutuila.
The church plans to construct health and mission centres and two residential buildings on the land.
The chief wildlife biologist at the department, Dr Lanie Berry, says they will strongly oppose any development:
"This 20 acres, of which the 5 acre, proposed development is part of, is the only remaining significant patch of this particular rainforest type that's left in American Samoa. We will certainly oppose any development, because any kind of development will effectively destroy the forest."
An earlier application by the church was rejected by the Project Notification Review System Board, which issues land use permits after strong opposition.