Vanuatu's Foreign Minister, Sato Kilman, says Fiji's interim administration will be asked why it is continuing with actions it has agreed to stop.
A report by an Eminent Persons Group, on behalf of the Forum, called for an end to human right abuses and for elections by early 2009.
But members of the public continue to report they have been roughed up at the barracks and the interim regime says elections will be held in June 2010.
Tehcnical groups are still working through some of the issues and will report back to the Eminent Persons Group at the end of next month.
But Mr Kilman, who is a member of that group, says it will impact on the region if the interim adminstration rejects calls for an early return to democracy:
"The Pacific Islands Forum was formed to be able work together, to stand together, and have one voice in the international circuit. But if Fiji is not going to play with the other group in the region you start to see, probably, the start of the disintegration of the PIF."
Sato Kilman remains optimistic that the interim administration will continue to work with the Forum group to achieve a successful outcome.