The Australian Foreign Minister, Stephen Smith, has confirmed Canberra had concerns about Fiji's planned Melanesian Spearhead Group-Plus summit set for next week.
The meeting was cancelled on Monday with the chair, Vanuatu Prime Minister, Edward Natapei, saying the MSG must uphold values of democracy and good governance.
Fiji's interim Government, in response, expelled the acting Australian High Commissioner, accusing her of interfering in Fiji's domestic affairs.
Mr Smith has rejected that but says his Government had raised concerns that Fiji's push to bring in other island countries, which are not members of the MSG, threatened the main regional body, the Pacific Islands Forum.
"Australia has been making representations that such a proposed meeting, a so called Melanesian Spearhead Group - Plus meeting, would be inappropriate because it would undermine the Pacific Islands leaders Forum as the premier forum for nations in the Pacific."
Fiji is suspended from the Pacific Islands Forum.