Duco is vowing to fight to keep Joseph Parker's heavyweight title bout in New Zealand.

Parker is due to take on Andy Ruiz in December but it's looking increasingly likely the fight will be moved to the United States.

Promoter Dean Lonergan is blaming the tight time frame to secure the seven figure sponsorship needed to host the event here and has asked the government for help.

But he told Mike Hosking they're not just relying on the possibility of that handout.

"There's not too many people who can stump up money in a short space of time to make things happen like this - they [the government] can certainly do it, but we're not just relying on that."

"We're in the commercial market talking to a lot of previous partners, a lot of new potential partners."