South African Rugby Union president Oregan Hoskins says that Argentina's potential participation in the Tri-Nations from 2012 was due to the fact that the competition needed "rejuvenation".
Sanzar announced on Monday that Argentina had been extended a "conditional" invitation to take part in an expanded TriNations tournament which would become a Four Nations Championship.
Argentina were however told that they would have to make sure that they have their best players available for the tournament and that Sanzar and Argentina would have to agree on a financial model that will make the Pumas' participation in the tournament financially viable as soon as possible.
"I'm really relieved that we've taken this huge step forward," Hoskins told the Cape Times.
"We have been working on it for a long time and it is good for South African rugby and good for Sanzar."
"We have been playing with three teams for a number of years and the competition needed rejuvenation."
Hoskins said that he was confident that Argentina would be able to field their best possible team.
"Former captain Agustin Pichot is the key man there and he has given us assurances that the best Argentinian players would play," he said.
"There are possibilities that their players could be spread out among the Super 15 teams.
"We have also asked the IRB to cover the shortfall of Argentina's participation in the first year."
"We hope that their participation will be financially viable in the second season."
The new format would for the Four Nations would the four teams playing each other on a home and away basis which equates to six matches per team (currently the teams play five matches) and a total of 12 matches each year.
The Four Nations would be played from mid-August (following the end of the new Super 15) for an eight or nine-week period through until October.
South African domestic rugby is expected to take a knock though as Hoskins said that the the effect on the Currie Cup would be minimised with a likely reduction in teams from 2012.
"We may have a reduced Currie Cup from 2012 onwards," he said.
"We still have to thrash out those details."
