Newcastle have made a four-year $4.5 million contract upgrade offer to Kalyn Ponga that will reportedly leave the door open for him to play in the 2023 Rugby World Cup.

Ponga, who has previously expressed a desire to play for the All Blacks, is off contract at the Knights at the end of next year and a free agent from November 1.

According to the Sydney Morning Herald, the Knights have tabled the huge deal deal that would include an option in Ponga’s favour for 2023.

That would in turn allow the 21-year-old to try his hand at the 15-man game if he desires, in a bid to push for a place at rugby’s global showpiece in France.

“We have obviously put a deal forward that we believe is in the best interest of the club, but also in the best interest of him,” Knights CEO Phil Gardner said.

“He could play for the All Blacks, the Wallabies, or he may end up going to Japan or Europe.

“We genuinely want the best for the young man and while ever he wants to play rugby league we want him to play here at Newcastle.”

Ponga has played 49 NRL games since his debut for North Queensland in 2016, but is already one of the game’s most marketable stars.