Ponga and Gagai were both born in Australia but switched their allegiance to the Kiwis this year, given their Maori descent and after changes to eligibility rules.
Gagai has previously represented Queensland in the State of Origin 23 times and has seven Australian caps, including in their 2017 World Cup final victory over England.
Ponga has also been a stalwart for Queensland but has yet to play a Test.
"We're very excited for this World Cup cam…