American Samoa has officially complained to the New Zealand government about a New Zealand research vessel which illegal landed at Swains Island two weeks ago.
The vessel, MV Echo, was charted by the Apia-based regional South Pacific Regional Environment Programme, SPREP.
The territory's member of the US Congress, Faleomavaeaga Eni Hunkin, has contacted the New Zealand Embassy in Washington for an explanation on why the boat had berthed at American Samoa's most remote island.
He says he expects a reply later this week.
Last week, the American Samoa Harbour Master, Silila Patane, said the vessel had committed an act of aggression and violated both international and American Samoan maritime law.
A Tokelauan official says the boat was travelling from Tokelau to Apia and its stopping at Swains Island was a mis-understanding.