The Northern Marianas is opposing the proposed listing of 23 local species under the Endangered Species Act.
The CNMI's Department of Lands and Natural Resources acting secretary Richard Seman says the government plans a "unified front" against the proposed listing.
The Marianas reed warbler is one of the so called endangered species.
But Mr Seman says it is not endangered because of low numbers but because it is found only on Saipan.
Rota holds 11 of the 23 proposed species and Mr Seman says it would be the island most affected should the listing go through.