Mo'unga, who has professed to a soft spot for rugby league, is in Brisbane helping the New South Wales Blues prepare for the third and deciding State of Origin match on Wednesday night.
Mo'unga told the Sydney Morning Herald he had been invited for "a bit of personal development" after playing at fullback in a practice game against the NSW side.
Mo'unga's older brothers both played rugby league and the 30-year-old had been tempted to play the 13-man code at school level.
Mo'unga revealed he was made a serious offer to join the Warriors in 2018, the year he played the first of his 56 tests.
"It got as serious as meeting with Stephen Kearney, my agent, my father-in-law and 'Sully' (Warriors recruitment manager Peter O'Sullivan)," Mo'unga said.
"The reason I stayed was because I played rugby and my only dream and goal was to be an All Black to play at a World Cup.
"It's one of those things you'll always have conversations with your mates, saying how it would have been awesome (to switch)."
Mo'unga began a three-season Japanese club contract after last year's World Cup and helped lead the Toshiba Brave Lupus to the domestic title.
He is ineligible for the All Blacks until his contract ends and told the Sydney Morning Herald he is "working towards" representing New Zealand at the 2027 World Cup in Australia.
Mo'unga was in the crowd when the All Blacks beat England in the first test at Dunedin this month, their first match under new coach Scott Robertson.
