The Pacific Islands Forum says it was not informed about Australia's proposal to send more than 200 police to Papua New Guinea next year.
An agreement on the deployment was reached in principle in talks in Port Moresby on Thursday.
Australia sent more than 200 officers to Solomon Islands in July in an operation backed by the Forum whose members have also contributed officers to improve law and order.
The Forum's secretary general, Noel Levi, says the deployment of Australians is a bilateral matter for PNG to decide.
Mr Levi says he doesn't agree with claims that PNG faces a law and order crisis.
"No. I don't agree because in PNG it is not a law and order crisis as such. As we all know, there have been continuing law and order problems in PNG, particularly in the urban centres such as Port Moresby. And of course we know PNG is a big country with over five million people. So the nature of the situation is a continuing problem that has been there all the time. It is not a crisis per se."