Argentina's President Cristina Kirchner has congratulated Pope Francis in a card on her Twitter page.
But local newspapers in Argentina are commenting on the President's acrimonious relationship with the new pope, who was formerly Archbishop of Buenos Aires.
The pair clashed publicly over the subject of same-sex marriage in 2010.
According to the popular daily Clarin, Kirchner's own husband, Former President Néstor Kirchner, has reportedly said there were "ups and downs" in their relationship.
A woman who claims she was once the girlfriend of Pope Francis said the pair broke up because he wanted to become a priest.
Pope Francis put his humility on display during his first day today, stopping by his hotel to pick up his luggage and pay the bill himself.
Julie Etchingham has spoken to Vatican insiders who have given her interesting details on the man chosen to lead the Roman Catholic Church.