RIO DE JANEIRO (AP) — A center-leftist's victory in Argentina's presidential elections is set to cement a rift between South America's largest nations, and suggests regional turbulence could extend for years.

Alberto Fernández and his far-right Brazilian counterpart Jair Bolsonaro have been antagonizing each another since August, and their statements since Sunday's vote signal that neither plans to relent.

In his victory speech, Fernández urged freedom for Brazil's jailed leftist former President Luiz Inácio Lula da Silva -- Bolsonaro's nemesis.

Bolsonaro, meanwhile, told reporters during a visit to Abu Dhabi that Argentina had "chosen poorly" and that he didn't intend to offer his congratulations.

The hostility portends difficult times for the Mercosur trade customs union that this year celebrated reaching a free-trade accord with the European Union after two decades of negotiations.