Global rugby was in uproar on Thursday when details of a proposed 'World League' involving 12 teams and no promotion or relegation were published by New Zealand media.
Reports said the competition would be limited to established Six Nations and Rugby Championship sides along with the United States and Japan.
'Tier Two' emerging European and Pacific nations, however, would be excluded from the competition for at least 12 years, also prompting a robust response from their players - and a denial from World Rugby, who said nothing has yet been decided.
New Zealand Rugby (NZR) chief executive Steve Tew also said no format had been agreed, and that the Tier Two nations needed to be included in discussions.
"We certainly need a pathway for teams that don't make the original cut," Tew said.
"We've made it very clear our position is promotion-relegation (and) in the medium and long-term (it) is going to have to be on the table.
"There must be a pathway for the countries around us to get into the big competitions when they're ready, and the same can apply to emerging nations in Europe."
Rugby Australia (RA) Chief Executive Raelene Castle also backed Tier Two nations' inclusion in the future shake-up.
"The competition model must provide opportunities for the Pacific Island nations and other developing nations to continue to grow and compete with Tier One nations," she said in an RA statement.
"While these discussions are progressing with ... World Rugby and the national unions, nothing has been agreed or finalised."
Leading players, including Ireland's Johnny Sexton and England captain Owen Farrell, criticised the proposal on Thursday, raising concerns over workload, increased long-haul travel, shortage of recovery time and a lack of opportunities for Tier Two nations.
FROZEN OUT
Daniel Leo of the Pacific Rugby Players' Welfare organisation (PRPW) said on Friday his 600 members were concerned about being frozen out.
"Now is the time for the voice of Pacific rugby to be heard through our players," Leo told the BBC.
"The days of colonialism are long behind us but this model that they're proposing is more reminiscent of those days," said Leo, who represented Samoa at the 2007 and 2011 World Cups.
"Everyone plays this game to progress and if there's a ceiling to how well you can do in this game then smaller nations probably just shouldn't play in the first place. I feel we're at a real crossroads in the sport."
Former England coach Stuart Lancaster believes the plan will not come to fruition.
"If you think of the number of players who come from the Pacific Islands and play rugby across the world, if anything we should be doing everything in our power to help them not to hinder them," he told BBC Radio.
"With the reaction to date, particularly from the players and this notion of no promotion and relegation and 12 countries included and everyone else excluded, it doesn't make any sense. I'd be very surprised if it got much traction."
(Reporting by Greg Stutchbury; additional reporting by Mitch Phillips, editing by Ian Ransom, Ed Osmond)
