Jason Taumalolo believes the Rugby League World Cup is an opportunity to promote Tonga on the international stage and has chosen to play for the Mata Ma'a as he did at the 2013 tournament.
Taumalolo, regarded as one of the best forwards in the game, has provided a massive boost for Tonga's World Cup campaign by deciding to make himself available for Kristian Woolf's team ahead of New Zealand.
However, he insisted he wasn't turning his back on the Kiwis and still hoped to continue his 10 Test career in the black jersey after the World Cup.
After playing for Tonga at the last World Cup in England, Taumalolo said he was keen to do so again and believed the tournament was a time when developing nations could compete on an even footing with the likes of Australia, New Zealand and England.
"I really enjoyed my time within the Tongan World Cup Squad last time and have had a long-time association with Tongan coach Kristian Woolf," Taumalolo said in a statement.
Under the new international eligibility rules, Taumalolo is able to choose between the Kiwis and the Mata Ma'a, for whom he qualifies through his Tonga-born parents.
He was also eligible for Australia after moving across the Tasman before the age of 13 but chose to play for New Zealand in 2014 and cannot change allegiances between tier-one countries.
"I see with the new international rule change an opportunity to represent both Tonga and NZ throughout my career," he said.
"I have and will always be proud to wear the Kiwis Jersey. I just feel the World Cup provides developing nations like Tonga and opportunity to play on the big stage and I would like to help them with their campaign."
Taumalolo's decision is a massive boost for Tonga, who will name their squad in Brisbane on Thursday.
Woolf is expected to also have Will Hopoate, Michael Jennings, Konrad Hurrell, Manu Vatuvei, Solomone Kata and Tui Lolohea at his disposal for the World Cup.
The Mate Ma'a play Scotland in Cairns on 29 October and Samoa in Hamilton on 4 November before taking on New Zealand at Hamilton on 11 November in a match which will now attract even greater interest and may have a bearing on which team finishes top of the pool.