The UN has banned Fiji from participating in future peacekeeping missions. Existing deployments will continue, but they will not be invited to participate again until Fiji returns to democracy.
This is an essential way of putting pressure on the interim regime. Fiji's military is a source of revenue for the country - they basically rent them out to the UN as mercenaries, and pocket the generous per diem payments the UN gives them. It's also a source of pride for the military. Cutting that off will target the people responsible for the coup in a significant way, and make it that much harder for them to pretend that everything is normal.
Now, if only they'd done this two years ago...