Indonesia says it is not in the Melanesian Spearhead Group (MSG) to undermine a push for self-determination in its Papua region.
A war of words between Fiji and Solomon Islands has broken out over Indonesia's admission, as an associate member, to the sub-regional group in 2015.
The Solomon Islands deputy prime minister Manasseh Sogavare accused Fiji of forcing other MSG countries to accept Indonesia.
But Fiji's defence minister Ratu Inoke Kubuabola has said this is not true.
A Solomon Islands' academic Tarcisius Kabutaulaka said letting Indonesia in was a mistake because it's openly trying to undermine the United Liberation Movement for West Papua which applied to join the MSG as a full member.
But an Indonesia's embassy spokesman in Australia Sade Bimantara said this is not why Indonesia joined the MSG.
"You know since the 1960s in Indonesia, we have been contributing towards peace, stability and prosperity in the Asia Pacific region and so all we have been doing in the Pacific is just expanding that sort of architecture and norm setting into the South Pacific region as well and working with Australia and working with New Zealand and other countries in the South Pacific region."
Sade Bimantara said the Papua region has full political and democratic freedom.
He said the United Liberation Movement for West Papua only represents the aspirations of exiled Papuans.