Sanzar chief executive Greg Peters has reiterated that the Super Rugby competition could not be expanded to accommodate a sixth South African team until 2015.
"What we have said is that we will always talk to our partners as we should have dialogue with the joint venture partners," Peters said.
"But we have sold our format of Super Rugby for five years, expiring in 2015, which has a conference format to it.
"If you don't have that, you don't have the format we sold the broadcasters and commercial partners until 2015."
This follows the SA Rugby Union's (Saru) decision at the end of January to include the Southern Kings in the 2013 Super Rugby season while the future of the current SA franchises was left hanging in limbo.
Earlier this month it was reported that the current five teams -- the Stormers, Bulls, Lions, Cheetahs and Sharks -- sent a letter to Saru threatening to boycott the 2013 season if any of the five were excluded from the competition.
Saru, however, refuted the reports, with the national rugby body's chief executive, Jurie Roux, setting the record straight.
"No threat of a boycott was made," Roux said at the time.
"But the franchises have made it plain that the only option to them is the expansion of Super Rugby.
"They also pledged their support for the Kings' inclusion in 2013 as well as for Saru's efforts to persuade Sanzar to include a sixth South African franchise."
Peters said any threat of a boycott by teams would be fruitless as they had agreed to the current format.
"The threat of boycott has been rebutted by Jurie Roux as the CEO of Saru," Peters said.
"The franchises are bound by terms of a joint venture contract and broadcasting contracts around the world, so the threat of a boycott is hollow."
The Sanzar boss said the option of expanding the competition had been investigated and found not to be viable.
"We have looked at the 16 team option in the past and within our current format it just doesn't work," he said.
"It would be a big ask to move away from what we have sold to our broadcasters and commercial partners for five years.
"Remember we are only just about to start year two of that new format.
"That is the position and we have considered and had a look at various options to try and fit 16 teams in and they simply don't work."
It has also been reported that Saru would have the backing of South Africa's broadcaster rights holder, SuperSport, in its negotiations for expansion which would give it some bargaining power.
Peters, however, said it was not as simple as that as there were a number of factors that would determine whether South Africa could be successful in their lobbying down the line.
"That is one of the major factors, obviously, the amount of money that the broadcasters across the three territories fund the game.
"They are key stakeholders and this is something the Kings have asked before.
"It is not just SuperSport, it is Fox Sport in Australia and Sky TV in New Zealand, and commercial partners Vodacom, FxPro and Investec who are naming rights sponsors of the competition.
"Plus the franchises, who now have built a commercial model on having eight home games every year, so obviously that needs to be factored in as well."
Peters said the issue would again be addressed at a Sanzar meeting in Sydney in March.