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.
French fishing vessels were trespassing says CEO of Malvatumauri National Council of Chiefs
Malvatumauri National Council of Chiefs said the activities of illegal fishing by French vessels in Vanuatu waters showed disrespect to the people of Vanuatu.
Malvatumauri chief executive officer Jean Pierre Tom, said the chiefs are disappointed because no permission was sought by the owners of the vessels for them to "harvest from the gardens" of the people of Vanuatu.
"With the Covid-19 pandemic, marine resources will sustain the livelihood of the people of Vanuatu," Tom said.
"He urged France not to add the pandemic woes with the issue of illegal fishing in Vanuatu water."
He described the actions of the French fishing vessels as trespassing.
Meanwhile, the French Embassy confirmed receiving Loughman's letter and that a response is being prepared in Paris.
Reports from New Caledonia indicated the three vessels belong to the Pescana Fishing company in New Caledonia.
The management of the company says their fishing vessels normally fished in that zone but in the New Caledonia waters, not the Vanuatu waters.
The company added they are allegedly not aware of the illegal fishing activities, and will contact the captains of the three vessels over the issue.