West Papua advocacy groups are concerned that if the Indonesian military receives sophisticated helicopters from the United States government it would increase its capability to carry out sweep operations in remote areas of West Papua.
Defence officials in Indonesia have announced plans for the government to purchase the AH-64 Apache helicopters.
A letter co-organised by the US based East Timor and Indonesia Action Network and signed by several organisations, is asking the US government and Congress not to allow the sale.
Edmond McWilliams from the West Papua Advocacy team, says the helicopters could give the military greater access to areas in the Highlands region.
"Our concern is that they would be used to give much greater range to the Indonesian security forces to carry the fight into very remote areas in West Papua to villages that perhaps have been beyond their range in the past, they would now be vulnerable to attacks in these sweep operations."