World Rugby president Bernard Lapasset has added further weight to calls for the structure of international rugby to be reformed.
Speaking ahead of a lucrative sponsorship announcement for the men's and women's World Sevens series, the head of the game's governing body suggested the Olympic programme next year is causing a rethink of the XV-man version's role in the game, adding that a new system was required to ensure growth and sustainability.
"We need to open up a new system for the 15-man game to bring the northern and southern hemisphere programmes closer together," said the Frenchman.
"I opened up the debate at the executive committee meeting in Dublin earlier this year. At the moment one has the Six Nations, which is successful and the Four Nations (southern hemisphere international competition), which is less so.
"We have to look at the possibility of getting a new model of competitions, to grow profitability and to make it as attractive as possible to broadcasters.
"What is the best format, the quality of the competitions, the safety of the players? It is great to create opportunities and to aid the development of rugby.
"The Rugby World Cup is the third largest sports event in the world, after the Olympics and the football World Cup, which is huge for us. However, we must maintain our level."
Lapasset added that he believed emerging rugby nations had the potential to shake up the world hierarchy in years to come.
"I think fifteens is more open, professionalism has opened it up," he said.
"The Fijians, Samoans and Georgians are playing more and more in the northern hemisphere club competitions, especially in France.
"The Georgians have a very good XV, while the Romanians are now showing signs of revival. The Americans, too, I believe will come through, because they embrace all sports in the US.
"Russia, though, is more complicated. Unless a sport is in the Olympics, they don’t invest in it."