In interviews with participants in the process, from business executives to government officials, there is still widespread confusion about how much and what exactly each firm is supposed to produce. Corporate executives say they face a bewildering number of requests from dozens of nations around the world, along with governors and mayors around the country, for scarce supplies. The White House has not said who will set the priority list for deliveries. And it is not clear that any of it will arrive in time for the cities and the states that are hit the hardest, including New York.

Yet, in declining to actually make use of the Korean War-era production act that he invoked last week, Mr. Trump is also avoiding taking personal responsibility for how fast the acute shortages of personal protective gear and lifesaving equipment are addressed…

Administration officials, asked why they have been reluctant to use the full force of the Defense Production Act to press industry into action, say the country is not in such dire straits. There is plenty of volunteer cooperation, they say, and there is always the implicit threat of ordering mandatory measures if they do not. Mr. Trump, at the news briefing, suggested an ideological concern as well. “We’re a country not based on nationalizing our business,” he said.