Boeing Chief Executive Dennis Muilenburg, makes an introduction during the annual shareholders meeting on April 29, 2019 in Chicago, Illinois.

Boeing, in the midst of defending its grounded 737 Max jets, says global demand for new airplanes is stronger than it previously thought.

The aviation giant released its long-term industry outlook at the International Paris Air Show on Monday, raising its global forecast for the commercial aircraft industry over the next two decades.

Boeing said the airline industry will need 44,040 new commercial airplanes worth $6.8 trillion by 2038, up 3% from $6.49 trillion estimated last year.

Boeing believes the biggest demand will be in single-aisle jets, where the company estimates airlines will need to make 32,420 narrow-body planes by 2038.

"We see continued sustained growth," Boeing Chairman and CEO Dennis Muilenburg told CNBC at the Paris Air Show.

His comments came on the same day Airbus launched a brand new plane, the A321XLR, which is scheduled to start flying in 2023. The launch customer for the XLR is Air Lease Corp, which leases hundreds of planes to airlines around the world.

"We're getting extremely strong expressions of interest from a lot of our customers globally," said Air Lease CEO John Plueger. "We believe it's going to be a blockbuster."

Air Lease has ordered 27 Airbus A321XLR planes.

— CNBC's Meghan Reeder contributed to this report.