United Airlines to add 10 new international routes. See where.

United Airlines said on Tuesday that it will add 10 international routes starting in 2027, extending the carrier's flight network to new destinations in Europe and Asia.  

The route expansion is the largest in the airline's history, according to United.

"We've been adding a lot of new cities each year in the past several years," CEO Scott Kirby told "CBS Mornings" co-host Gayle King in an interview. "It's more this year, partly because the aircraft manufacturers have caught up."

The new flights build on United's existing network, which consists of 160 international destinations, according to the airline. 

United's new international routes:

• San Francisco (SFO) to Okinawa, Japan
• Washington Dulles (IAD) to Toulouse, France
• Newark (EWR) to Luxembourg City, Luxembourg
• Newark (EWR) to Marseille, France
• Newark (EWR) to Ibiza, Spain
• Newark (EWR) to Valencia, Spain
• Newark (EWR) to Terceira, Portugal
• Newark (EWR) to Ljubljana, Slovenia
• Newark (EWR) to Olbia (Sardinia), Italy
• Newark (EWR) to Catania (Sicily), Italy

United said it will start serving the 10 new international hubs as early as March 2027. Of those, eight will depart from Newark Liberty International Airport in New Jersey.

"The FAA has, after years, finally done what we asked and slotted, and now Newark is the most reliable of the three New York airports," Kirby said. "Now that you have Newark running the best it's ever run, that enables us to add eight new destinations out of Newark across the Atlantic."

Kirby has repeatedly called for changes at Newark to help address flight congestion, including adding "slots," industry lingo for authorization windows that the Federal Aviation Administration gives to airlines to take off or land at an airport. Slots ensure that the number of scheduled flights per hour doesn't exceed the airport's maximum capacity, Kirby said in a letter to employees last year.

Kirby on airfare costs

Kirby also addressed flight costs, which remain elevated amid strong traveler demand. Inflation data released last month shows airfares were up more than 25% in July from a year ago.

"Air travel still remains a great value," Kirby said on "CBS Mornings," noting that average airfares are 13% lower than they were before the pandemic. "But we are bouncing off a kind of artificial low. When COVID happened and air travel demand collapsed, airfares collapsed as well. So they're coming back to more normal levels."