The Pacific Agreement on Closer Economic Relations (PACER) Plus Agreement will come into force on 13 December after the Cook Islands became the eighth signatory state to ratify it to be able to come into effect.
The Cook Islands on 14 October, joined Australia, Kiribati, New Zealand, Niue, Samoa, Solomon Islands and Tonga, who have already ratified the agreement.
Minister for Trade and Economic Development, Hon Samiu Vaipulu said it was a significant milestone in the Pacific's journey towards enhancing economic integration and growth.
"The PACER Plus Agreement will encourage and promote trade and investment that is essential for our region's recovery and growth during and after CoViD-19 and reinforces our commitment to our Blue Pacific and the strengthening of regionalism."
PACER Plus is a regional trade, development and economic cooperation agreement between Pacific Island Countries and Australia and New Zealand covering trade in goods, services and investment.
PACER Plus negotiations commenced in 2009 and the Agreement was opened for signature in Nuku'alofa on 14 June 2017.
It has been signed by 11 countries. Signatories who have yet to ratify the agreement are Nauru, Tuvalu and Vanuatu.
After 13 December, the Agreement will come into effect for any other signatory 60 days after they notify Tonga, as the Depository of the Agreement, that they have ratified it.