The Forum secretariat in Suva says members are deeply concerned about recent turn of events in relation to the New Zealand High Commissioner.
The commissioner, Michael Green, was expelled for allegedly interfering in Fiji's domestic affairs.
The Forum says while noting Fiji's statement that this was a bilateral issue, Forum members are deeply concerned when something of this nature occurs.
It says the relationship between New Zealand and Fiji is an important one for the region generally, and the region inevitably suffers when events such as this disturb it.
The Forum working group on Fiji also says Fiji's final position on the assessment of an election timetable will be known after the interim cabinet meets on Tuesday.
A report by experts says elections can be held in November of next year while the interim administration has said they will have to wait until 2010.
A New Zealand academic says the rift between Fiji and New Zealand is a blow for the region.
An associate professor of political science at Canterbury University, Dr John Henderson, says the expulsion will hit the Pacific Islands Forum whose headquarters is in Suva.
"The problems with the Forum are probably the most serious aspect of this incident. Fiji is just so important to the region as the headquarters of so many regional organizations, most importantly the Forum Secretariat. When Fiji goes off the rails, the whole region is destabilised. So when you need an effective Forum it's going to be very hard to operate."
Dr John Henderson