A new Pacific trade deal could prove divisive in the region, according to NZ Green Party MP Barry Coates.
PACER Plus is designed to enhance the economic development of Pacific island countries through greater regional trade and economic integration with Australia and New Zealand.
The agreement covers 12 island countries, but missing from it are the two biggest economies among the island nations, Papua New Guinea and Fiji.
While PACER is being touted by Australia and New Zealand as a great deal for the island countries, Mr Coates - a veteran of the aid and development sector - said they get few benefits.
The MP said the deal also went against the emphasis placed on regionalism by Australia and New Zealand.
"They have put a lot of their aid programmes in the past to promote regionalism but now they have signed a trade deal that misses out on the two major countries," Mr Coates said.
"And I think it stands to potentially drive a wedge between the Pacific and I think it is a very unhealthy dynamic to have."
A formal signing of the agreement between 14 nations is scheduled to take place in Tonga in June.
The countries participating in PACER Plus are New Zealand, Australia, Cook Islands, Federated States of Micronesia, Nauru, Kiribati, Niue, Palau, Republic of Marshall Islands, Samoa, Solomon Islands, Tonga, Tuvalu and Vanuatu.