President Trump announced that the United States was grounding Boeing’s 737 Max aircraft, reversing an earlier decision by American regulators to keep the jets flying in the wake of a second deadly crash involving one of the jets in Ethiopia.

The Federal Aviation Administration had for days resisted calls to ground the plane even as safety regulators in some 42 countries had banned flights by the jets. As recently as Tuesday, the agency said it had seen “no systemic performance issues” that would prompt it to halt flights of the jet.

“The safety of the American people, of all people, is our paramount concern,” Mr. Trump said.

The order came hours after Canada’s transport minister said that newly available satellite-tracking data suggested similarities between the crash in Ethiopia and another accident last October.

The crash of Ethiopian Airlines Flight 302 killed all 157 people on board, and took place just minutes after takeoff. In October, a 737 Max 8 operated by Lion Air, an Indonesian carrier, crashed in similar circumstance and 189 people were killed.