Super Rugby could be in line for another expansion in 2016 with a sixth team from South Africa already in progress and an Argentinian club side possibly joining the competition.
New Zealand Rugby Union CEO Steve Tew says Super Rugby could expand to 17 teams and hinted at interest in a club side from Japan.
"It's well documented that South African want a sixth team and that's currently a plank in the work that's being done," Tew said.
"We all want Argentina to be able to take control of some of their professional players so putting an Argentinian team into the competition is also a very strong desire."
A four-country club competition presents problems when it comes to draw structure and travel costs.
"The challenges of running a competition across the Indian Ocean between Australia, New Zealand and South Africa are significant enough and, frankly, it's one of the reasons why it's the toughest competition in the world," Tew said.
"You throw in Argentina, which we believe is the right thing to do, then it becomes even more complicated , so I don't think we have to make any apology for saying it's going to take us a bit of time to get this right."
Tew was also encouraged by the reception the All Blacks received in Japan when they travelled there for a Test in Tokyo and says that market is something they are exploring along with the rest of the Asia-Pacific region.
"I think we'll welcome Japan into this competition at some point in time. Whether it's in the next phase of development of this competition, I'm not quite so sure," Tew said.
"It's a much bigger step to be able to sustain a pro team in a league like this that play's week in week out.
"We haven't dismissed the possibility of interest from other parts of the Asia-Pacific bases. Our friends in the USA and Canada are also asking to be kept in mind. But if it's hard running a competition across the southern park of the oceans then you can imagine what it's going to be like if you start going up and down them."
An expansion to the world's premier club rugby competition comes off the back of a financially burgeoning game at home with all 26 New Zealand provincial clubs predicted to make a profit according to third quarter projections.
"At the end of the third quarter, all of the 26 provincial unions are looking at a modest of better profit so we should have no unions losing money in 2013." Tew said.