BUENOS AIRES, Argentina — Argentina's Senate began what's likely to be an all-night voting marathon on the details of President Javier Milei 's sweeping proposals to slash spending and boost his own powers early Thursday, shortly after giving the plan overall approval in a narrow vote as thousands of protesters clashed with police outside.

Senators voted 37 to 36 late Wednesday to give provisional approval to the two bills after a daylong heated debate while thousands of protesters poured into the streets, burning cars and throwing Molotov cocktails as hundreds of federal security forces pushed back with rounds of tear gas and water cannons.