The Treasury secretary says President Milei will meet with President Trump at New York on Tuesday. Mr. Milei has promised to lower taxes, cut government budgets, and end stifling regulation that has hindered economic expansion. The International Monetary Fund says Mr. Milei’s policies have started to work to undo years of left-wing Peronism. The Argentinian senate also recently passed bills to hike government spending on several big programs, a threat that could derail Mr. Milei’s austerity push. In a series of X posts on Monday, Mr. Bessent says the South American country is a “systemically important US ally” and the United States backs Mr. Milei’s reforms.