United Airlines is readying its biggest-ever international expansion, betting that adding nonstop connections to far-flung, social media-friendly locales will keep passengers booking trips abroad.

The Chicago-based carrier on Tuesday announced new destinations ranging from Ljubljana, Slovenia and Marseille, France to Ibiza, Spain. "People's desire to see and explore the world is bigger and brighter than ever," said Scott Kirby, United's chief executive, at an event in Newark, N.J.

United is looking to extend its global reach to cement its lead over rivals and overtake Delta Air Lines as the most profitable U.S. carrier. Kirby has even floated megadeals with Delta and American Airlines as a way to continue expanding around the world and to better take on foreign airlines.

The Chicago-based airline already flies to more international destinations than its top competitors. United has for years embraced a strategy of adding nonstop flights to off-the-beaten path destinations, beyond the most popular and heavily visited European capitals.

It has added nearly 60 international destinations to its route network in the past decade, and has made its summer route reveal into an annual event, complete with Easter egg hints dropped on its social-media accounts. United is hoping that another slew of exotic locales will help capture travel trends and spark new ones, even as high ticket prices weigh on customers' pocketbooks.

The Slovenian capital Ljubljana, to United, is the sort of city seasoned travelers want to see but couldn't get to directly.

"This is one of the most Instagrammable, beautiful cities out there," said Patrick Quayle, United's senior vice president of global network planning and alliances. "It's an example of United Airlines being creative and putting destinations on the map where I don't think any other airline would think about it, because you can't square it off in an excel spreadsheet."

Americans have clambered to travel overseas in recent years, and airlines are racing to add service to match their zeal for new experiences. Tired of Rome and Florence? Next try Bari, or Palermo. Portugal and Greece have taken off.

United's new routes next year will include flights from Newark to Terceira, an island in Portugal's Azores, as well as Sardinia and Sicily. Valencia, Spain and Okinawa, Japan will also be added.

Rivals have been bulking up their international destination portfolios as well. Delta started flying to Sardinia and Malta this summer, and announced plans to fly to the Philippines from Los Angeles next year. American this summer added Budapest and Prague.

U.S. government data shows that international travel has cooled off some this year, but airlines have said European trips remain in demand despite long immigration lines and oppressive heat.

"Demand is incredibly strong," Quayle said. And the summer travel season also now extends deeper into fall, with airlines continuing to operate seasonal service to some destinations into October or November, he said.

Other new places on United's map, like Luxembourg and Toulouse, France-where Airbus is based-are important business corridors. United also announced new flights from Washington, D.C. to Milan; Los Angeles to Osaka, Japan; and Denver to Paris.

United also plans to restart its service from San Francisco to Tel Aviv. Its 10 new international destinations include eight that no other U.S. airline serves nonstop.

Many of the United's new routes will be served by the Airbus A321XLR, a single-aisle jet designed for long-haul flying that United said will play an important role in its next phase of international growth.