Morales told the newspaper La Razon that he communicated directly with the pontiff, who confirmed his travel plans.
"I have received this message: I will be there in July," Morales told the daily.
Morales long has expressed desire for a visit from Francis, 78, hoping he might play a role in resolving a longstanding maritime dispute with neighboring Chile.
The Argentine pope was born Jose Bergoglio on December 17, 1936 in Buenos Aires.
The announcement about his South America travel came as Francis on Monday wrapped up a triumphant visit to the Philippines and Sri Lanka, seeking to promote the Catholic Church in one of its most important growth regions.