Wallis and Futuna has become an associate member of the Pacific Islands Forum.
The admission of the French territory was agreed to by the Forum leaders at this week's summit in Nauru.
Wallis and Futuna had until now been a Forum observer like the three US territories in the Pacific.
The French overseas minister Annick Girardin has welcomed the Forum decision, saying it consolidates the territory's integration into the region.
Last year, Wallis and Futuna was admitted to the Polynesian Leaders Group, which is the largest sub-group in the Pacific Islands Forum.
Two years ago, the two other French territories - New Caledonia and French Polynesia - were admitted as full Forum members.
The Forum's other associate member is Tokelau, which is administered by New Zealand