A February change to State of Origin eligibility rules made it possible for Kalyn Ponga to represent New Zealand internationally while still playing for Queensland.
The rule change allows players who meet existing Origin criteria to represent their state regardless of which country they play for internationally.
Ponga is set to make his New Zealand debut against Australia next Thursday in the World Cup opener in Sydney.
The Knights captain spent roughly five years in New Zealand as a child and said he was proud to represent his family's heritage.
He has played three matches for the Maori All Stars, and represented the Junior Kangaroos and Australia at the World Cup nines in 2019.
Speaking at the team hotel in Coogee, Ponga said, "I didn't want to pull on a jersey that - not that I wouldn't be proud - but I just felt like this is me,"
He added, "I'm just grateful that this opportunity is here. I'm excited to make the most of it and get out there and represent the people."
On the eligibility change, he said, "I thought it was the right decision (to change the rules). I think the game's only getting bigger, and to strengthen both stages - the Origin arena and international - I was just grateful that I can actually have this opportunity and represent my people."
Ponga said, "It's going to be a proud moment. I know my family will probably have tears in their eyes. Obviously doing the Haka and everything before the game, we'll be proud."