Alberto Fernández's future cabinet will include Martin Guzmán as economy minister.
Guzmán's appointment comes after weeks of rumours. The 37-year-old will run the key ministry and his leadership will be crucial, given the urgency of the debt owed to the International Monetary Fund (IMF) and private bondholders, as well as Argentina's deep economic turmoil.
Argentina has received US$44 billion from the IMF to date, and it owes roughly US$315 million to private bondholders.
Just days before the formal announcement Friday, Guzmán, together with Nobel Prize winner Joseph Stiglitz in New York, proposed a two-year delay on paying off extenral debt owed and, through an agreement with creditors, extending those payment plans to stimulate capital.
"It's great that he's decided to leave New York and return to Buenos Aires. I have great confidence in him. He's a young man who is very prepared, and we have worked together for weeks," said Fernández.
Guzmán is the director of a debt restructuring programme at Columbia University in New York City. He also is a macreconomics professor at the University of Buenos Aires.
The president-elect will opt out of receiving the final payment of the IMF's US$57 million loan.