The fate of Boeing’s 737 Max 8 is uncertain after more countries barred the aircraft from flying, even as US officials declined to act. The plane was already suspended in China, Indonesia, and Ethiopia after an Ethiopian Airlines crash killed 157 people on Sunday. Today, the UK, Australia, Poland, and Singapore became the latest countries to ground the 200-seat Boeing 737 Max 8. Hours later, the European Union’s top aviation safety agency followed suit.

Just six months ago, the same model of airplane crashed off the coast of Indonesia, and all 189 passengers on board were killed. Both crashes are still being investigated, but aviation officials around the world aren’t waiting to take action. The UK’s Civilian Aviation Authority said it lacked “sufficient information” as to the cause of Sunday’s crash of Ethiopian Airlines Flight 302, but it would be stopping commercial flights involving the jetliner as a “precautionary measure.” Australia and Singapore’s respective aviation authorities characterized the move as a “temporary measure.”

Statement: Boeing 737 MAX Aircraft.



The UK Civil Aviation Authority has issued instructions to stop any commercial passenger flights from any operator arriving, departing or overflying UK airspace.



You can read the full update online: https://t.co/xa1BUR7wJk pic.twitter.com/AsmhLElF0K — UK Civil Aviation Authority (@UK_CAA) March 12, 2019

Soon after, the European Union Aviation Safety Agency, which represents Britain, Germany, and France, joined the wave of suspensions of Boeing 737 Max 8 aircraft.

The 737 Max 8 is still approved to fly in US airspace after the Federal Aviation Administration declined to issue guidance to carriers. Investigators from the FAA and National Transportation Safety Board are expecting to learn more after recovering the flight data recorder and the cockpit voice recorder from the Ethiopian Airlines crash.

“The FAA will issue a Continued Airworthiness Notification to the International Community (CANIC) for Boeing 737 Max operators,” the agency said in a statement. “The FAA continuously assesses and oversees the safety performance of U.S. commercial aircraft. If we identify an issue that affects safety, the FAA will take immediate and appropriate action.”

In a statement, Boeing said it still has confidence in the 737 Max 8, despite the groundings. But US lawmakers are urging the Trump administration to follow the lead of other countries in grounding the plane until the cause of the crash can be determined. Sens. Mitt Romney (R-UT), Richard Blumenthal (D-CT), and Dianne Feinstein (D-CA) issued statements calling on authorities to temporarily ban the aircraft.

But President Donald Trump appears to be in no rush to make a call. In a pair of tweets on Tuesday morning, Trump decried the complexity of modern aircraft and called for a return to “simpler” models. He made no reference to the recent crash, nor the status of the 737 Max 8.

Airplanes are becoming far too complex to fly. Pilots are no longer needed, but rather computer scientists from MIT. I see it all the time in many products. Always seeking to go one unnecessary step further, when often old and simpler is far better. Split second decisions are.... — Donald J. Trump (@realDonaldTrump) March 12, 2019 ....needed, and the complexity creates danger. All of this for great cost yet very little gain. I don’t know about you, but I don’t want Albert Einstein to be my pilot. I want great flying professionals that are allowed to easily and quickly take control of a plane! — Donald J. Trump (@realDonaldTrump) March 12, 2019

The Boeing 737 Max 8 has been a popular plane since it came on the market in 2017; more than 4,000 planes were ordered within the first six months. In the wake of the Ethiopian Airlines crash, more than a dozen airlines around the world said they would ground their 737 Max 8 planes.

With the addition of Norwegian Airlines to the list on Tuesday, nearly half of the global fleet of 737 Max 8 planes have been grounded. At least 12 other carriers, including American Airlines and Southwest Airlines, continued to fly them on Monday.

Update March 12th, 1:48PM ET: This story has been updated to include new countries and safety agencies that have grounded the Boeing 737 Max 8.