New Zealand Rugby chief executive Steve Tew believes it's too early to say the proposed Nations Championship won't go ahead because of concerns in the Northern Hemisphere.
World Rugby's concept appears to have hit a road block after England's Rugby Football Union (RFU) declared possible relegation from the Six Nations would have "catastrophic" consequences for them.
The Nations Championship is World Rugby's vision for the global game after Japan 2019 and takes the format of a new cross-hemisphere league that would see the top teams from the Six Nations and Rugby Championship collide at the end of the year.
Relegation and promotion based on overall league performance is a foundation of the plan in the hope it will create depth by offering tier two teams a place among the elite.
Tew said England's concerns are not news to New Zealand Rugby and all nations are still working through the proposal.
"We all think the concept's got real merit, it's great to have something new in front of us," Tew told RNZ.
"But we and the rest of our Sanzaar colleagues have also said we're not saying yes to it either, at this point in time.
"There are a number of things we'd like to work through and that process is underway. To rule it in or out at this stage we think is premature."
Acting RFU chief executive Nigel Melville is determined to avoid the scenario - however unlikely - of a two-year spell outside of the sport's most successful annual tournament.
It has been speculated that were England to drop into a tier two competition, then Twickenham might have to be sold to cover for the inevitable collapse in revenue.
Tew said they understood the concerns their English counterparts had with certain aspects of the proposal.
"We've known all along the Six Nations have serious concerns about the relegation component that's on the table.
"[Melville] has probably put it in more stark terms overnight but relegation is not an easy thing to deal with and if it happened to any of us we'd have to readjust the way we ran our businesses.
"That's the concern they have."
Melville also expressed the RFU's reservations about what would happen in the case of relegation, stating there needed to be a credible tier two tournament.
But Tew felt a more established competition for tier two teams wouldn't necessarily change England's views on the proposed test championship.
"From what I've heard from the Six Nations, I think frankly they'll never accept promotion-relegation is a good idea.
"Having said that, [Melville is] right that the tier two competitions right now don't have enough structure to them.
"All of this is trying to solve some of those long-standing issues, so we have a genuine chance to bring more countries up to another level, so the World Cup is a more competitive competition, and ultimately challenge those of us in the Rugby Championship and Six Nations."
Tew said all nations had two more weeks to reach their conclusions on the proposal, but stressed that deadline was only to commit formally to a period of negotiations and due diligence, not commit fully to the concept.
He added the RFU had expressed that timeframe could present a challenge for them in terms of making a decision.
- RNZ, with AAP