MEXICO CITY—As Covid-19 cases and fatalities mount across Mexico, the country’s next richest businessman is publicly defying well being suggestions meant to prevent the spread of the new coronavirus, sparking a confrontation with the governing administration.

Ricardo Salinas Pliego, who controls an empire of retail, banking, broadcasting and other companies worthy of far more than $10 billion, has criticized governing administration tries to sluggish the virus by buying nonessential companies shut and imposing social-distancing steps.