The order, which signaled a shift from the hands-off approach the White House had previously taken toward A.I., followed debates over how to gain control of A.I. models without disrupting innovation.

The changes, after Meta’s legal losses in two child safety cases, are aimed at limiting harmful content shown to teenagers on Instagram, Facebook and Messenger.

The billionaire has stated many plans for his businesses, but has delivered only some of what he said he would, when he said he would, according to a Times analysis.