The Vanuatu government is unhappy with France after French fishing vessels were spotted fishing illegally near Aneityum, and the Matthew and Hunter islands.
The small, uninhabited islands of Matthew and Hunter have been the subject of a long running territorial dispute between Vanuatu and France, with both countries claiming sovereignty over them - in France's case, it says they are part of its territory of New Caledonia.
The dispute remains very much unresolved.
In the latest development, Vanuatu's national fishing monitoring agency confirmed the three long-liner fishing vessels based in Noumea were sailing in these disputed waters.
Commissioner of Vanuatu Maritime Affairs Toney Tevi said Prime Minister Bob Loughman had written to Paris expressing his disappointment at France's unilateral and provocative actions.
"Activities such as this do not help at all, in any case, in many countries, when you come across situations like this, they don't help at all, by trying to resolve this dispute.
"So, our prime minister has expressed his utmost disappointment with how French have been going on fishing in the vary territory which is being negotiated between France and Vanuatu."
Vanuatu claims sovereignty over Matthew and Hunter.