Taumalolo said a big reason behind his decision was the opportunity to represent a Pacific Island nation. He said he hoped his decision will inspire other young Tongans to "choose rugby league paths and become great players in the future".
"I was with Woolfy (coach Kristian Woolf) in the last World Cup for Tonga and I enjoyed my time with him, so that kind of helped.
"Obviously with the rule changes they applied earlier this year, it gave a platform for us bigger names to represent smaller nations and tier-two nations.
"It was a good opportunity to make them a more competitive country in rugby league. That was one of the biggest motivators for me."
Taumalolo said he was proud to represent his Tongan heritage, despite being born in New Zealand.
"It will mean a lot, especially for my family. Although I was born in New Zealand, the rules gave me the chance to go back and play for Tonga and my heritage.
"What it means to play for Tonga and their people, that's everything to me. I hope I make them proud."
Several of Taumalolo's former Kiwi teammates were critical of his decision, and selector Tawera Nikau said it would be a difficult decision if Taumalolo wanted to re-join the Kiwis in the future.
"Those will be tough decisions that we've got to make and discussions that we've got to have once we get to that position," Nikau told the Herald.
"But if you're picking players for this World Cup, you've got to show a bit of loyalty to those guys that have put their hand up and said they want to be playing.
"Those are the discussions that the selectors will have when it gets to the time but if you're looking at players that have said 'yep, I want to be a part of this' that are 100 per cent committed to the black jersey, that are respecting the jersey, and all those that have gone before them, you'd certainly take that into consideration.
"When you look at the guys that you really want in the team, it's those guys that are going to do the hard yards when the going does get tough, you want them to be there."
When it comes to his ex-Kiwi teammates, Taumalolo said he hasn't heard from any of them since his decision except for Cowboys teammate Te Maire Martin.
"He's shown his support. Te Maire's happy, and that's probably all I've heard from.
"They're all great footy players and have been playing great for their respective clubs. We're definitely expecting a lot of passion from them. It should make a great game of footy."
Taumalolo was criticised for not communicating with Kiwis coach David Kidwell before or after making his decision, and it seems like that is unlikely to change.
When asked by The Courier Mail if he would play for New Zealand again in the future, his reply was telling.
"I can't answer that at the moment, sorry."
