The international environmental group, the Sea Shepherd Conservation Society, says it is surprised Fiji's interim government says it is not welcome in the country.
The regime has issued a statement saying radical groups like Sea Shepherd, which sensationalise fishing practices for the purposes of self-promotion, will not be tolerated.
The group's Director of Shark Conservation, Julie Andersen, says the organisation does not act illegally and wants to help countries in the region enforce marine reserves.
She says in the Galapagos Islands, Sea Shepherd has donated a ship, helped with training and invested more than 1.2 million US dollars in new technology.
She says a similar model could be introduced in Fiji.
"Right now the Fijian government is determining whether or not they're going to declare their waters the world's largest shark sanctuary so of course that makes us very excited and what we would love to do is begin conversations with Fiji around how we can help enforce those waters."
Julie Anderson says Sea Shepherd would like to send a delegation to Fiji to start talks on how to work collaboratively.