The United States on Wednesday grounded Boeing Co.'s 737 MAX series aircraft in the wake of an Ethiopian Airlines crash that killed 157 people.

An order by the Federal Aviation Administration came after Canada joined about 40 countries in grounding the planes. The suspension involves the entire global fleet of 371 737 MAX aircraft, according to Boeing.

(American Airlines' Boeing 737 Max 8)[Getty/Kyodo]

"The agency made this decision as a result of the data-gathering process and new evidence collected at the site and analyzed today," the FAA said in a statement.

"This evidence, together with newly refined satellite data available to FAA this morning, led to this decision."

Sunday's crash in Ethiopia came less than five months after a 737 MAX 8 belonging to Indonesian budget carrier Lion Air crashed into the Java Sea on Oct. 29, killing all 189 people on board.

An FAA official said Wednesday the data suggested similarities between the two accidents.

Speaking at the White House, President Donald Trump said Boeing is "working very, very hard right now and hopefully they'll very quickly come up with the answer, but until they do, the planes are grounded."

"The safety of the American people, and all people, is our paramount concern," Trump said.

Boeing said it supported the U.S. government's decision to ground the planes, though the company continues to have "full confidence" in the safety of the 737 MAX.

"We are supporting this proactive step out of an abundance of caution," Boeing President Dennis Muilenburg said in a statement.

"We are doing everything we can to understand the cause of the accidents in partnership with the investigators, deploy safety enhancements and help ensure this does not happen again," Muilenburg said.