U.S. President Donald Trump on Wednesday issued an emergency order to ground Boeing 737 MAX 8 and MAX 9 aircraft after a crash in Ethiopia that killed 157 people.

“We are going to be issuing an emergency order of prohibition to ground all flights of the 737 MAX 8 and the 737 MAX 9 and planes associated with that line,” Mr Trump told newsmen at the White House.

According to him, the FAA is prepared to make an announcement very shortly regarding the new information and physical evidence received from the site, and from other locations and through a couple of other complaints.

Boeing shares, which were up earlier in the session, fell two per cent to 367.70 dollars.

The shares have fallen about 13 per cent since the crash, losing more than 25 billion dollars of market value.

Meanwhile, Germany’s federal agency responsible for investigating air accidents will not analyse the black box from the Ethiopian Airlines plane that crashed on Sunday, casting uncertainty over the process of finding out what may have caused the disaster.

“This is a new type of aircraft with a new black box, with new software. We can’t do it,” said Germout Freitag, a spokesman for Germany’s Federal Bureau of Aircraft Accident Investigation (BFU).

The move leaves unclear the destination of the black box, which may yield vital details of what caused the Boeing Co 737 MAX 8 to plunge to the ground, killing 157 people.

A spokesman for Ethiopian Airlines had said earlier that the black boxes recovered from the crashed plane would be sent to Germany for analysis.

Canada also grounded 737 MAX jets, saying satellite data suggested similarities to a previous crash involving the same plane model.

Countries around the world have grounded the 737 MAX jets or banned them from flying over their airspace since the Ethiopian Airlines flight crashed soon after taking off from Addis Ababa on Sunday.

The still unexplained crash followed another involving a Boeing 737 MAX in Indonesia five months ago that killed 189 people.

Although there is no proof of any link, the twin disasters have spooked passengers, led to the grounding of most of Boeing’s 737 MAX fleet and hammered shares in the U.S. plane maker, the world’s largest.