The president of the Papua New Guinea autonomous province of Bougainville, Joseph Kabui, is upset he has not been invited to the Melanesian Spearhead Group meeting under way in Vanuatu.

The special meeting, which was called by PNG's foreign minister, Sir Rabbie Namaliu, is also being attended by Fiji, Vanuatu and Solomon Islands.

Mr Kabui says he cannot believe he has not been invited to attend, especially since one of the main issues on the agenda is the ongoing presence of the former Fijian soldiers on Bougainville.

He says under the autonomous peace agreement, if an issue arises, the Bougainville government must be involved.

"This is absolutely disgusting and I'm absolutely disappointed. I don't know what sort of agenda that the national government has. Any matters relating to Bougainville, any issue relating to Bougainville, whether it is a security issue or whatever, the autonomous government must be involved."

Mr Kabui says he'll be officially protesting to the national government over the issue.

But, he says progress is being made on the ground in attempting to resolve the issue and discussions are continuing.