Organisers believe Argentina will add a new dimension when they join an expanded Tri-Nations competition alongside Australia, New Zealand and South Africa.
The South Americans will compete in the rebranded Rugby Championship from August 2012.
"The invitation is a defining moment for southern hemisphere rugby," said Sanzar chief Greg Peters.
"The Pumas play an exciting brand of rugby."
Argentina enjoyed an impressive World Cup, running eventual champions New Zealand close in the quarter-finals, and their high performance chairman Manuel Galindo is delighted with the new link-up.
"For years, Argentine rugby has been seeking to participate regularly in a tournament like this," he said.
"Playing in the Rugby Championship makes us really proud and will compel us to work harder at what we are doing.
"We must celebrate being part of this tournament."
The 12-match Championship schedule kicks off on August, 18 2012 and will feature games in all four countries, with Australia taking on New Zealand in the first fixture in Sydney. Argentina will make their debut the same day when they visit South Africa.
The All Blacks have dominated the Tri-Nations competition since its inception in 1996, winning 10 of 16 championships.