World Rugby chairman Sir Bill Beaumont has called an emergency meeting to discuss the future of the international game.
Representatives from all tier-one countries - along with Fiji, Japan and the players' union - will gather in Dublin at the end of the month.
"I look forward to a constructive debate with my colleagues and productive outcomes," said Beaumont.
"Only by working together in the interests of the global game can we achieve something truly impactful in this important area for rugby's future global growth."
Beaumont added that "no decisions have been made" amid concerns over player welfare and the marginalising of the likes of Georgia and the Pacific Islands.
World Rugby insists it is in support of a promotion and relegation system in the league, but the Six Nations remains opposed to the concept.
This has contributed to the impasse, with sources fearing the Six Nations' stance could prove to be a roadblock for the development of emerging nations.