The Assembly of First Nations' Chiefs in New Brunswick says the project must protect the environment and guarantee the ability to exercise treaty rights before it can support the development.
The group says the First Nations should also be able to participate in managing the pipeline and receive benefits from it.
On Tuesday, TransCanada Corp. (TSX:TRP) announced it was seeking binding commitments from shippers before deciding whether to file the necessary regulatory applications for the development.
The Energy East Pipeline project would involve converting an existing 3,000-kilometre natural gas pipeline so that it could carry crude into Quebec.
If it proceeds, it could also see a 1,400-kilometre extension that would ship oil into the port city of Saint John, N.B., home to the Irving Oil refinery, Canada's largest.