The administration of U.S. President Donald Trump is resisting growing domestic and international calls for it to ground a new American-made jetliner which has crashed twice in six months, killing nearly 350 people.
The president is engaged in discussions about the Boeing 737 Max-8 aircraft, according to White House officials who did not specify with whom Trump is speaking.
Boeing CEO Dennis Muilenburg reassured Trump in a phone call Tuesday that the aircraft is safe, according to company officials.
White House officials confirm the call occurred but are declining to discuss details of the conversation, which occurred after Trump complained on Twitter that planes "are becoming far too complex to fly."
It is not clear who initiated the call.
"Split second decisions are needed, and the complexity creates danger," Trump also said on Twitter. "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!"
Trump, however, stopped short of calling for the jet to be grounded until the cause of the crashes are found and planned modifications of software are installed for the aircraft's automatic anti-stall system, which may have played a role in both accidents.
Boeing also said in a statement Tuesday it has no plans to ground the Max 8, while the U.S. Federal Aviation Administration said its own review of available data shows no basis for grounding the planes.
Since Sunday’s crash in Ethiopia, aviation authorities responsible for the airspace of dozens of countries, including China, Turkey, Indonesia, Brazil, South Korea and the entire European Union, have issued orders temporarily prohibiting flights of the 737-Max 8, suddenly making it the world’s most unwelcome airplane.
A number of U.S. senators from both parties, on Tuesday, called for the Federal Aviation Administration to do the same thing.
"These planes need to be grounded until they are inspected by Boeing and FAA," former U.S. Transportation Secretary Ray LaHood told CNBC. "You can't compromise safety."
Two labor unions representing flight attendants have also added their voices to the calls for temporarily halting commercial use of the jet.
However, the pilots' union for Southwest Airlines takes a different stance.
The MAX "is safe based on the facts, intelligence, data, and information we presently have. We fully support Southwest Airlines' decision to continue flying the MAX and the FAA's findings to date," said SWAPA President Jon Weaks in a statement.
"We have full confidence in the aircraft and our crew members, who are the best and most experienced in the industry," American Airlines, the other big domestic operator of the Max 8, said in a statement.
The airlines acknowledge some passengers are changing their travel plans to avoid flying on the Max 8 aircraft.
The head of the U.S. Federal Aviation Administration on Tuesday said his agency is urgently reviewing "all available data" and has not yet found any "systemic" issues or basis to "order grounding of the aircraft." Acting administrator Daniel Elwell, in a statement posted by the FAA on Twitter, said if new information is found the agency will take "immediate and appropriate action."
Authorities in several countries, including the United States, have raised concerns that the Max 8's automated anti-stall software can be erroneously activated by incorrect flight data and may have been a significant factor in both crashes.
"We have to review and see what actually took place," White House Press Secretary Sarah Sanders said on Fox News on Tuesday. "We know that a lot of people in the industry have started to voice concerns about the amount of technology and taking the power out of the hands of the pilots, you saw the president talk about that in his tweets earlier today."
Sanders added that administration officials are "going to be in constant contact through the Department of Transportation, the FAA and make a determination at the appropriate time."
Boeing, whose stock price has fallen 11 percent in two days, announced on Monday that it is developing a "flight control software enhancement for the 737 Max, designed to make an already safe aircraft even safer."
The initial crash of the Max 8 involved a Lion Air domestic flight in Indonesia on Oct. 29 of last year which plunged into the Java Sea.
This past Sunday's Ethiopian flight, according to witnesses, nosedived minutes after takeoff from Addis Ababa on an international flight to Nairobi in neighboring Kenya.
The flight data and cockpit voice records of Ethiopian Flight 302 have been recovered, the airline announced on Monday.
WATCH: Debate over grounding plane