The maritime boundary between Niue and American Samoa was first delimited in 1997, and it extends along a broadly east-to-west directional bearing for 279 nautical miles. Niue is an island nation in free association with New Zealand, while American Samoa is a territory of the United States. Niue and American Samoa are both positioned in the South Pacific, with American Samoa situated north of the boundary line and Niue to the south.

This maritime boundary divides the overlapping portions of the States’ maritime entitlements derived from the United Nations Convention on the Law of the Sea (UNCLOS). Prior to the Agreement having been reached, technical work was completed by Niue and the United States to update the existing data of the mean low water line along the shores of the islands, which was then used in calculating the equidistance maritime boundary. Despite having reached the Agreement in 1997, its final ratification was not achieved until 2014.