The United States has grounded Boeing's 737 MAX 8 planes, joining a host of countries which have done the same in the wake of Sunday's deadly Ethiopian Airlines crash.
It was the second time the U.S. Federal Aviation Administration has halted flights of a Boeing plane in six years.
The FAA said fresh evidence as well as newly refined satellite data prompted the decision.
It had previously ruled the jetliner was airworthy.
Major American airliners had decided to keep flying the planes.
An investigation into the cause of Sunday's crash is still underway.
Boeing said it continues to have full confidence in the safety of the 737 MAX 8, but said it had agreed to ground the planes as a cautionary measure.