Argentina elected libertarian outsider Javier Milei as its new president on Sunday, rolling the dice on an outsider with radical views to fix an economy battered by triple-digit inflation, a looming recession and rising poverty.

Milei, who rode a wave of voter anger with the political mainstream, won by a wider-than-expected margin. He landed some 56% of the vote versus just over 44% for his rival, Peronist Economy Minister Sergio Massa, who conceded.

"The model of decadence has come to an end, there's no going back," Milei said in a defiant speech after the result, while also acknowledging the challenges that face him.