The Cairns Post reports that Manning has led the charge for a joint NRL bid with PNG since early 2018, going so far as to meet with former chief executive Todd Greenberg and chairman Peter Beattie about the plan.
While the pandemic impact has put a dampener on discussions over the past year, and the NRL's current administration have expressed little interest in the idea, Manning was adamant the door remained open.
"The prospects are still there and we're keen to talk, but it would require a financial agreement with the Federal Government and backing from a very high level in PNG," he said.
"I think we've got a fair way to go, but we're keen on it — we've always been keen on it. This is the only way our city will get a stadium."
It comes days after Papua New Guinea Prime Minister James Marape said his country was aiming to have its own NRL team by 2025.
The PNG government recently signed a sports partnership agreement with Australia, which could help pave the way for a PNG-affiliated side to enter the NRL in the future.
Manning maintained a joint bid with Cairns would be the ideal proposal.