There have been five meeting between the Association of University of the South Pacific Staff (AUSPS) and the university's management, but the two sides remain in dispute over FJ$1.3 million.
The association general-secretary Rosalia Fatiaki told RNZ Pacific workers will go on strike if current mediation fails.
In March, the regional university staff were given the mandate to strike over pay issues following members of unions representing staff voting in favour.
Fatiaki said staff were originally asking for FJ$15million, but are now asking for FJ$7.6m.
"We were advised from the Ministry of Labor that once we are in mediation, we cannot go on strike," she said.
"So that's the thing we are caught in there with mediation happening."
Fatiaki said it means that only when mediation cannot progress can the union invoke strike action.
Another meeting between the unions and management is scheduled for Thursday.
Fatiaki said the union is "hopeful" there will be a resolution soon to stalled negotiations.
"We're hopeful that they want to resolve this matter and hopefully when we come to the table on Thursday, that there'll be some resolution to that deadlock amount."
In March, USP told RNZ Pacific "it is fully engaged in the process with the Association of the University of the South Pacific Staff (AUSPS) and Union and welcomes further negotiations to reach an amicable solution."