Boeing said in its statement yesterday: "We acknowledge and regret the continued difficulties that the grounding of the 737 Max has presented to our customers, our regulators, our suppliers, and the flying public".
The 737 MAX has been grounded worldwide since mid-March, as Boeing updates its flight control software at the center of two crashes in Indonesia and Ethiopia that together killed 346 people within a span of five months.
Today's bad news contributed to a 3.3% decline in the price of Boeing's shares, which stood at $313.37 at the end of the trading day.
Boeing confirmed on Monday that it temporary halted production of the 737 MAX in Washington state in recent days.
Calhoun said the company is not considering scrapping the Max and expects it will continue to fly for a generation.
A spokesman for the US Federal Aviation Administration said the 777X flight was expected soon "but the timing is entirely up to Boeing".
The Max 8 was also the airline's most fuel-efficient aircraft.
He also disclosed Boeing is starting with a "clean sheet of paper" on a new midsize airplane but it is not clear if the company is scrapping the existing design.
Boeing has estimated the costs of the 737 MAX grounding at more than $9 billion to date, and is expected to disclose significant additional costs during its fourth-quarter earnings release on January 29.
The good news - if there is any to be found in this completely messed up situation - is that the workers who were previously tasked with constructing the 737 Max will remain employed with Boeing and will not be laid off or furloughed, according to the company.
In its statement, Air Canada said decisions about returning the jet to service would be based on its own safety assessment following "approvals by the FAA and Transport Canada".
The company added that it will provide more information next week about its efforts to safely return the Max to service when it releases its quarterly financial results.