Argentine presidential candidate for the La Libertad Avanza alliance Javier Milei waves to supporters after winning the presidential election runoff at his party headquarters in Buenos Aires on November 19, 2023. AFP
"President Biden spoke with President-elect of Argentina Javier Milei to congratulate him and discuss the importance of continuing to build on our strong bilateral relationship," a White House statement said.
It said a readout of the call will be released later.
Milei, a 53-year-old economist who has vowed to scrap multiple government departments and sometimes campaigned by waving a chainsaw from the stage, trounced Argentina's long-dominant Peronist coalition on Sunday.
Voters punished the government for decades of economic decline, with annual inflation currently at 143 percent.
Milei has vowed to ditch the peso for the US dollar and shut down the central bank -- which he accused of rampant money printing to finance government overspending -- in a bid to halt inflation.
During his campaign he said he would slash state spending and ditch about 10 government ministries, among other controversial proposals.
He later toned down some of his rhetoric, leaving uncertainty over his actual plans.
US Secretary of State Antony Blinken had congratulated Milei in a statement on Sunday, adding that the United States also applauded "the robust democratic process through which the Argentine public has spoken."